hAP ax2 here too but I work wired most of the time so I don't tend to be stressing the Wi-Fi. My set-up is a private and a guest network, also used by my neighbour. In order to do some testing/diagnostics on my hAP ax2, I put the guest network on a spare hAP ac lite. It's been like that for several months.same situation here, with hap ax2 - random disconnects of one client
I've just realised that I've not had to tell my Amazon Echo is restart the radio for months either... my hAP ax2 and ac lite are right next to each other. So Amazon Echo connected over 5G to hAP ac lite, completely solid. Looking at reservations, some devices have been connected for several days.