Only PCs can't connect to 5GHz Wi-Fi - Windows 10 AC600

Current device: Asus X756UX-T4244T
Wi-Fi adapter: FRITZ! AC430 and TP-LINK Archer T2U AC600
Router: Unitymedia Connect Box
( All drivers updated )
Hey,
after seeing how big the speed difference between my 2.4GHz and 5GHz is I tried connecting every device with 5GHz. My iPad and S9 connect with 5GHz instantly without any problems. When I try to connect with any PC after about 5 seconds of loading my Wi-Fi adapter (AC 430) disconnects, then after like 3 seconds the adapter reconnects and it says "cannot connect to this network". Exact same thing with the other adapter and with other PCs.
Connecting to 2,4GHz is working 100% fine. When I use the same SSID for 2.4G and 5G it automatically connects to 2.4G even tho I have 5G as preferred in Windows.
I've really tried everything I could find already: Tried 2 different Wi-Fi adapters, they ALL support 5GHz and 802.11ac - Tried 3 different PCs (all Windows 10), reset my network settings, drivers, password is 100% correct, restarted router multiple times, tried all USB ports, changed SSID so 2.4G and 5G are not the same anymore, tried every channel < 50 and all Wi-Fi standards, checked all settings for the adapters + windows, disabled firewall, enabled high-performance mode on my notebook, unplugged everything....

This is very very weird because all my devices except PCs connect to 5GHz. When connecting with a PC the Wi-Fi adapter resets during the process and it fails to connect. It feels like they are being blocked by something. Since my 3 PCs don't connect and the process looks exactly the same (Adapters reset/disconnect while trying to connect) I'm sure it's not a software issue. The adapters are also brand new so they're not the problem. What's the difference between a mobile/iPad Wi-Fi card/adapter and a PC Wi-Fi card/adapter? Why can my mobile devices all connect to 5GHz but my PCs can't? Has anyone ever fixed or experienced this? What else could I try?

Thanks in advance

Welcome to the forum. The main thing of 5g is the range is a lot shorter then 2g so you may need to be a lot closer

Please update the specs in the "My Computer" section:

System Specs - Fill in at Ten Forums
In the left corner below in your post you find 'My System Specs'.
After clicking it you can find a link a little below that says 'Update your System Spec', click on this link to get to the page where you can fill in your system specs.
System Info - See Your System Specs - Windows 7 Help Forums

Include PSU. cooler, case, peripherals and anything attached to the computer by wired or wireless (mouse, keyboard, headset, printer, xbox, USB wireless network card, etc.)

The opening post did not mention a printer.
If there is a printer please turn it off and reevaluate wireless connections with 5 GHz.

Samuria said:

Welcome to the forum. The main thing of 5g is the range is a lot shorter then 2g so you may need to be a lot closer

Hey,
thanks for the fast response. That was the 1st thing I've tried when facing this issue but sadly placing a notebook right next to the router didn't fix the issue.

- - - Updated - - -

zbook said:

Please update the specs in the "My Computer" section:

System Specs - Fill in at Ten Forums
In the left corner below in your post you find 'My System Specs'.
After clicking it you can find a link a little below that says 'Update your System Spec', click on this link to get to the page where you can fill in your system specs.
System Info - See Your System Specs - Windows 7 Help Forums

Include PSU. cooler, case, peripherals and anything attached to the computer by wired or wireless (mouse, keyboard, headset, printer, xbox, USB wireless network card, etc.)

The opening post did not mention a printer.
If there is a printer please turn it off and reevaluate wireless connections with 5 GHz.

Hey,
do you think that could really help since I've already tried connecting with 4 different PCs which all have different specs? I tried unplugging everything once so my mouse/keyboard and other devices won't be the issue... I also don't have a printer. I feel like the router is blocking all PCs because every single smartphone/tablet is able to connect to 5GHz without any problems. But why does it matter whether it's a PC or a smartphone/tablet since all my PCs can connect to 2.4G? All my adapters support 5GHz and the Wi-Fi standards I've tried. It's really confusing.

I ran into this problem at my brother's home. He had too many devices connected to the 5ghz network. So any device being added was only connecting to 2.4ghz. He ended up buying a newer mu-mimo router that didn't have this problem.

A cheap USB Network adapter from your local electronics store (BestBuy, Walmart, Target, Microcenter, etc.. [just not RadioShack, RIP])

Most "5GHz" adapters are compliant to certain frequency bands. Some odd models can't seem to connect past channel 38 due to poor design (or old really). If this laptop is a need, you can certainly replace the inside chip, but that comes with real electrical dangers if you don't know battery concepts.

A cheap USB adapter will fix your day. Cheers

If any of the above assumptions wind up false, I apologize, just relating from my own personal headaches with 5,000kHz real-time onetime pad pseudo-random encoding hardware.

ram1220 said:

I ran into this problem at my brother's home. He had too many devices connected to the 5ghz network. So any device being added was only connecting to 2.4ghz. He ended up buying a newer mu-mimo router that didn't have this problem.

As I said, I'm able to connect 5 smartphones/tablets but not a single computer, even if I disconnect all other devices

You can see your wifi adapter’s capability by opening cmd.exe as administrator, cd to your user documents folder and entering” netsh wlan show wlanreport” This explains the WLAN report. https://support.microsoft.com/en-us/...network-report