I just upgraded my RT-AX88U about 2 hours ago with Alpha 3 from Alpha 2 and it updated just fine. It certainly sounds like you've installed this before so ignore this if you already know it: Make sure you are unzipping it into a folder first and then pointing the update at the...
Merlin lost his magical powers briefly. He's been training with Harry Potter and seems to be at about half power again. Once Harry has time to completely finish his spell scribing and passes that on to Merlin I'm sure we'll have new releases again.
Updated to alpha dirty with no issues seen thus far.
My entropy was all over the place (down as low as 1050 a few minutes after reboot) but this was the high:
admin@RT-AX88U-B690:/tmp/home/root# cat /proc/sys/kernel/random/entropy_avail
2482
As you've shown on your account - The signature information is a good place to put that "context" so that people know what features (beyond plain vanilla) they are running. I personally run piholes with unbound so I put all of my "extra stuff" on those rather than my routers. I am guilty...
No clue if this is the problem but I recall some issues in the past that needed to have your browser cache cleared. Try clearing your browser cache and then try to connect with a fresh browser.
If you/others can't figure it out you may want to just consider connecting it via Ethernet. You'd benefit by it always being available during wireless restarts, channel changes, lower latency (not by much, but it is something) etc...
I can't say enough good things about setting up Unbound on...