Can disabling DNS cache cause network instability months later?

Hi all, I've got a question, and I'll give the background just below.

On Monday my rig that's been stable since April suddenly starting getting Network Link disconnect/lost every 30 seconds. After 3 days of trying everything, including pulling out my hair, I accidently seem to have resolved the issue by re-enabling DNS cache, which I'd disabled a few months ago through a registry change.
I seem to have a solution, but I've no idea what caused the problem to begin with, or even is this is the real solution.

A bit more detail. On Monday my computer suddenly started getting network link disconnects every ~30 seconds. As this machine is essential, I immediately started trying to find and resolve the issue (of course, nothing worked). The machine had been stable since I built it, even when I added a TP-Link TX401 10GBe in April, to take advantage of my 10GB symmetric connection.

1. The most recent update I'd done was a few hours previously, an Intel Xe graphics drive 30.0.100.9955. I had a system restore so I went back to that (which includes reboots, of course)
2. I did winsock/interface resets using netsh and used ipconfig to flushdns and release and renew
3. I did sfc /scannow, and dism to check, scan and restore health
4. Checked all NIC drivers and settings (everything up to date, nothing had changed recently)
5. Checked cables/router
6. Checked the motherboard NIC (same issue, eliminating a HW issue ont he TP-Link)
7. Checked for Viruses and malware
8. Did a complete network reset
9. Tried static IPs
10. Disabled all boot-time programs

At this point I was a bit stumped. If it was a HW problem, it could only be at the motherboard level, I figured. I boothed to safe mode with internet, and low and behold, no problems with either NIC.

I rebooted to normal mode and the problem was back. Looking at Network Connections and Device Manager, one thing that had annoyed me was vEthernet adapters appearing and disappearing all the time. I'd heard this was due to DNS Cache being disabled, so I re-enabled it to stop that behaviour and, as I mentioned, I was suddenly back to stability.
So, I've got a solution but no idea where the problem actually lies (I'd disabled DNS Cache due to privacy concerns, btw).
The Intel driver obviously wasn't responsible, which was as expected. The only thing I can think of now is that there was a Windows update that only triggered something after the reboot from the Intel driver installation, so I'm wondering if anyone else has noticed an issue like this.
My OS is Windows Pro 21H1 build 19043.1320. Looking at the Updates history the last one was one on the 8th, KB5006365, Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10. It says it requires a reboot but I don't recollect if I rebooted or not. Could this has caused an issue?
(P.S. system specs are up to date in my profile)

Paul Black said:

Hello @XXX,

I have noticed that you have NOT had ANY replies, so I thought that I would try and help.

If you Disable the DNS Cache, it would actually be slower, because retrieving Resolutions from a Server is MUCH slower than retrieving them from the HDD/RAM. Therefore, DNS Lookups will be FASTER with it Enabled.

There could possible be instances when you run into problems with the DNS Cache, and in this circumstance, it is recommended that you Clear the Cache.

Have a look at these for some interesting background information . . .

> Why You Should Disable DNS Caching
> How to Flush DNS Resolver Cache in Windows 10

I hope this helps.

Thanks for the reply. Indeed, in point 2, above, I did flush the DNS cache with no success. It's true that the cache should speed up access. As i said, I re-enabled the caching and my problem disappeared, but I've no idea where the problem came from to begin with!