Welcome to our community, Bobby!
You are correct. Reach works well with the WPA2-Personal security configuration, but WPA3 can be problematic. However, I believe Patrick should notice other app instability if this is the case. But, just to be sure, @Bnom, please double-check the security settings of your mobile hotspot.
Aside from that, there is a chance the source of the issue is the dynamic IP of your hotspot. We have a support tip where you can find the method to set up a static IP address for your network. Could you please give it a try?