Having issues every day since being upgraded to a SH5

As above, recently got upgraded to a SH5 from a 3 - now I'm having issues every day with it - the connection will randomly drop out on the incoming side once or twice a day, with a lot of post-RS errors (it's often much, much higher than these which are the current ones):

The wifi is terrible too - it'll often drop the 5ghz network completely and everything will drop back to the 2.4ghz network, sometimes everything reconnects, other times nothing will work until I change the channel back and forth on the router and let it all come back up  (even worse, the channel changing bug where it won't change channel unless you also change channel width and then change it back, is STILL there in the software and that's a bug I reported probably 4-5 YEARS ago, come on, really?!)

Didn't have any issues with the SH3 like this, possibly a faulty SH5? Anyone had similar issues?

I'm also getting awful speed drops, even when the errors on the incoming side stop accumulating, I'll have maybe 60mbps download speed, instead of 1000, and nothing will fix it bar power cycling the router.