I recently loaded Moode 9.3 on two Pi 4Bs. I haven’t had any display issues using an 9th gen ipad. I am one s/w release back from the very latest. Album view is just as fast as it was on ver 8. The config screens are slower than album view, but seemed about normal. There is a parameter to change to make them go a little faster, if you are doing allot of changes and testing. I doubt it matters, but I have just been using the IP address of the Pi.
PS: On the 5G Wi-Fi
PS: On the 5G Wi-Fi