Hello Russell, you are correct that Tawe is no longer in development and therefore we are not testing it on new devices as they hit the market. It's actually been removed from sale completely although those that have previously purchased it on a phone/tablet will be able to re-download it and if you have a subscription to our desktop services which included Tawe the support team will help you download it if you need a fresh copy.
I'm not sure if the issue you are facing on your new device is linked to any Android or Samsung changes but I would recommend uninstalling/reinstalling on your device just to make sure it's installed correctly.
If you go to My Apps and Games within the PlayStore items you have previously purchased but are not currently installed will be in your Library folder
Just had a thought on the original issue. It could be a permissions issue for the app accessing your gallery.
Can you please ensure you grant Tawe with permission to use your Microphone and Storage
Go to settings
Enable Microphone and Storage
Relaunch the application
Awesome, glad we got to the bottom of the issue!