RT-AX88U unable to connect devices

[sdc]

I just installed RT-AX88U_3004_388.8_2 thinking I can sort out my intermittent connection issues with this router but the same happens.
How can I troubleshoot the connection issues (devices just refuse to connect including my Samsung S23 Ultra) I do have about 100 devices connected (IoT overkill in my house) and it may be related?
It really makes no sense, I have a very old and cheap RT-AC51U which is not experiencing the same issue so I do blame the AX88U

I am seeing this device spamming the log, not sure what it is.

I also see IPs going up as far 192.168.0.255 but I don't have that many devices so I increased the network to /23 on my ISP router to allow up to 192.168.1.254 but still isn't fixing the issue

 

[Ripshod]

If you updated to 388.8 from 388.7 or earlier then it's likely you'll need to factory reset and rebuild from scratch without restoring from backups. That's been my experience - getting that out there before the nay-sayers get here.

 

[PunchCardBoss]

you'll need to factory reset and rebuild from scratch without restoring from backups

Yep.

Method 2 factory reset.

[Wireless Router] ASUS router Hard Factory Reset - Method 2 | Official Support | ASUS USA

 

[sdc]

If you updated to 388.8 from 388.7 or earlier then it's likely you'll need to factory reset and rebuild from scratch without restoring from backups. That's been my experience - getting that out there before the nay-sayers get here.

I just installed over the official ASUS one, no restore from backup but I guess the same thing.
I will do a factory reset and take it from there first.
Also why not just use the reset button?

 

[sdc]

Think this router is trash inbound, factory reset method 2, same thing, existing devices connect, my phone and anything new does not, on the 2.4g band.
Time to bin it and swap with ubiquiti perhaps

 

[Squall Leonhart]

S23 and S24 randomised mac do not work properly with this router.

 

[sdc]

Yeah I have it set to use actual mac, but it's not just that, can't seem to add any iot device to it anymore either, maybe I hit the device limit, but makes no sense since there are less than 100 devices on the 2.4g, about 110 across 3 different APs and only this one is giving trouble