This has to be the worst customer service I have seen in along time. It's like insurance, you never know how good or bad it is until you need them. Well Roku, you suck. The update of 9.3.0 has cased me nothing but issues and yet Roku says nothing. The true test of a product is how well a company will respond to an issue. Roku get a F, in many forms and some in 4 letter words.
Fix the issue with 9.3.0 update, now. I will now look pass Roku when its time to update or purchase something new, this is just plan poor service on Roku's part.
RokuOS 9.3.0 is without a doubt their worst point release rollout in recent years, and even the "stable" and recent 4194 build is problematic to say the least.
That being said, sometime between today and the end of next month (sooner more likely than later), Roku will announce new player models, and a new OS version (most likely RokuOS 10, though there is a slim chance of a 9.4.0 release), that will likely rollout through the end of the year.
Whether the next firmware update contains fixes to the specific issues you experience or not, I highly recommend obtaining other alternate streaming devices/platforms, for a multitude of reasons (including but not limited to bad software (firmware/app) updates, and app carriage/compatibility/functionality limitations issues).
You can get them for as little as $25-50: Amazon FireTV 4K stick for $25-50, TiVo Stream 4k for $50, or the Xiaomi Mi Box S 4K for $50.