One website displays as text on 3 browsers

On Windows 10 laptop, all sites load properly except for one. (It worked earlier today and suddenly stopped)
I've tried loading in Firefox, Edge and Chrome. All display same way, text only.
Here is a screen snip to show what it looks like

Site is http://www.fasttech.com
I've rebooted modem, router, rebooted laptops, FlushDNS on the laptop. Same issue.
Same page displays fine on android phone but not on android tablet.(both running 4.4.2) or other Android devices running various Android versions.
Another Windows 10 laptop on the network displays the same page as text.
I connected to my neighbor's WiFi, the page loads correctly...

Thinking it must be a network issue I reset the modem to factory defaults and restored the config to one I saved over a month ago. Tried the site again, same problem.
After all that I ran network troubleshooter on the site, it returns:
Windows received an HTTP error message: 403 (Forbidden) from "fasttech.com"
Are they blocking part of their page from my ip or is it something on my side?
I'm at a loss, looking for ideas...help...

That was a fast reply...thanks.
Ran all commands as admin with success declared on all. Site still returns text as displayed above. It asked to check "I am not a robot" and captcha. It didn't do that in the past even after clearing data. However if I clear data and go to the site when connected to my neighbor's WiFi, it goes straight in.
Also, forgot to mention some other stuff I tried, I changed the router to different DNS chosen by NameBench. Neither the ISP assigned DNS or the ones entered from NameBench make a difference. Ran a Malwarebytes and antivirus scans, found nothing.
Any other ideas?

Caledon Ken said:

Does your neighbour use same ISP?

Nope, different ISP, so I get an ip address in a different range.

Caledon Ken said:

So multiple devices going through connection can't load this page. You mentioned phone works, does it iof you shut off cellular?
Have you tried Google DNS servers. I saw you had changed DNS servers.
They are listed in this tutorial although this tutorial is for a future Windows.
Change IPv4 and IPv6 DNS Server Address in Windows
Do you have IPv4 and IPv6 running?
You said your reset router and then loaded older config. What happens when you reset router and do nothing, run as is. Might suggest a cable connection so you don't have to work around wireless passwords

Phone is working on WiFi, no cell connection. Oddly I discovered my Son's phone works too, Both Samsung.
Google DNS makes no difference.
My ISP doesn't support IPv6.
I tried from a wired connection after resetting router to factory, same issue.
I wonder if the issue is Cloudfare related since the website issue started when the capcha challenges started popping up. On the site in question I was completing an online purchase and for some reason it failed. It was after that the captcha started popping up. Perhaps my ip was flagged due to my attempts to complete the purchase. I ended up completing the transaction from my neighbor's WiFi.
From Cloudfare site linked below...
"A site visitor to a website that Cloudflare is protecting can see a captcha for the following reasons:
1.The IP address you are on has shown problematic activity online recently in one of our data sources. If you would like to look your IP up, then please look your IP up at Project Honeypot. If the IP address shows data for malicious activity, you can see why there. You can also attempt to whitelist your IP directly on that page by connecting from that IP."

My ip didn't appear on the Project Honeypot site but I asked to have it whitelisted anyway. I contacted my ISP to see if they may be of help as well.
Why do I see a captcha or challenge page (Attention Required) trying to visit a site protected by Cloudflare as a site visitor? Cloudflare Support

Thanks a lot for your input on this strange problem. Any other thought would be appreciated.

Seems the Project Honeypot whitelist worked, website looks normal again after the whitelist request propagated, even the Cloudfare site renders properly now (didn't know it wasn't until I saw the difference).
Thanks for your help! Much appreciated.

Just wanted to add a snip of what the Cloudfare site looked like before ip was whitelisted:


and after ip was whitelisted: