extreme WIFI disconnectivity on dell precision m6800

Hi,

I have dell precision m6800; with dual band wireless-AC 7260. I have been using it for nearly 2+ years but since day 1 my internet gets disconnected on it's own. I have to stop the wifi from task manager and start the wifi again and connected to my available wifi; some times i have to disconnect/connect several times.

At first i thought i am sitting further from the wifi or my wifi router is over whelmed or this could be windows 10 playing tricks with me or maybe driver isn't compatible with window 10. But now i am starting to doubt the my wifi device/card is not in 100% working condition.

First kindly guide what could be the possible  reason for this constant disconnectivity?

Secondly if this is my WIFI device/card i am thinking of buying a new device. Kindly guide should I go for the wifi card which will be plugged in motherboard? or for some latest wifi adapter of tp link or d-link AC-1300 or so or could go for  wifi 6 adapter? would my system even be able to fully use the latest wifi 6 speed? (yes i will by wifi 6 router later =D ).

If i have to go for the built in one... which one is the best among the provided list of by dell ? attached a  screen shot of the wifi from dell precision manual m6800 or could i go for some other not mentioned, latest in-built card? if yes kindly do guide on this as well.

Thanks in advance guys and really appreciate your help.