I've been on a quest to figure out why this card sucks so bad. I think a big part of the problems lie with the card/router combination. For the last few months I have owned/tried; Linksys: WRT1900AC, EA6400, EA6350; Netgear: R6250 and R7000; Asus AC2400; Belkin F9K1113.
Here is a quick summary of what I have found-
Linksys
WRT1900AC - the 2.4GHz channel would drop constantly. I thought the one I bought was just defective so I bought another. This one dropped the 2.4GHz channel as well. This one had the best range but I noticed some staggering while I was playing online games. It just seemed a bit sluggish. The link speed was pretty good but ultimately took it back.
EA6400 - the range was terrible and it also dropped the 2.4 channel. I took it back
EA6350 - Link speed was terrible. I couldn't connect to the router above 300Mbps. It would initially connect at 866.7 but would drop down to 292.7 and rarely got over 300 if ever. I took it back.
Netgear
R6250 - There were so many routers that I can't remember the specifics of why I took this back.
R7000 - This one is the only router that would consistently keep a strong link speed. It is what I am using currently and will report back if I end up taking it back but I think I may stick with it.
Asus
AC2400 - this is one of the most expensive units on the market. the link speeds seemed to fluctuate and I would rank this as the third best I have used. I still have this but will most likely take it back
Belkin
1200AC - this is my second best. very basic but had all the features you need. Link speed was fairly constant around 700Mbps. If the Netgear doesn't work out, I will probably stick with this one. For $100 I think this is probably the best bang for the buck.
Ultimately I think this Intel card is finicky and flaky. I think the real solution is to replace the card because it shouldn't be this difficult to keep a steady high speed link. This combined with the fact that it doesn't connect after wakeup and the other connection issues makes replacement of the card the only real solution.