Is there nothing happening or something you might be doing when these failures occur?  Anything in your environment that could be interferring?

Have you looked at the rest of your wireless network, such as the router?  Does the router keep any logs?

Have you checked the Events tab on the Adapter's properties in the Device Manager?

Hard to say if changing the card is absolutely necessary.  The device is different in that it uses components on the chipset to operate.  So chipset drivers may be important or necessary.  Win 10 updates can change things and may have installed a driver that started the problem.  Are you keeping track of the driver version the device is using, and what is that version..?

There are others with dropping Wi-Fi problems.  Folks over on the ASUS forums are having the same situations with the AC 9560, which is the 2x2 version of your card.  These are happening in Desktop and laptop systems.

Folks in this forum have been having the same problem with other brand cards.  Other than reinstalling drivers or perhaps even changing out the card, about all you can do is be aware of what, when and how the problem occurs to see if you can find a cause.  Disconnects may even be caused but a certain amount of corruption in the data being received.

If you have a friend with a network you could use for testing, it might give different indications.

It sounds like the Wifi adapter may be failing. Run diagnostics (F12 at the Dell splash screen) and watch for any errors.

I've had my XPS 15 9500 for a few weeks and my wifi keeps dropping so long as it is using 5g.  I switch over to the 2g and all's good.  I have all kinds of devices - including a Lenovo company laptop - that all use the 5G with no problem.  I contacted Dell support about it the first time.  It took around 1.5 hours for them to fix it but it worked for a few days past it being fixed.  Most of the time it works fine on the 5G the next day and while sitting on my office desk.  I'm guessing that it has to do with the heat build up.  That would explain why it goes out after an hour on my lap but now when sitting on the desk - and why it works fine the next day after cooling all night.

mines been doing the same for months...xps13

have a feeling it is the driver vs high speed router as it drops out just when it reaches top speed.

checked last night latest driver was 2017??

could be wrong

Try this solution:

I managed it out disabling bluetooth in bios and also disabled hw switch off of wifi and bluetooth. No driver reinstalation needed.

I have an XPS 17 with the AX211 card and I had the same problem where 2G networks worked fine but 5G would drop off repeatedly.

I ended up rolling back the driver to version 22.160.0 and the problem went away.