New Custom sounds are ignored

[Rayearth]

Poco F4 GT with xiaomi.eu stable 14.0.6.0 here

Notification and ringtone sounds set up with Options > Sound & touch > Ringtone > Choose local ringtone > Sound menu are completely disregarded and the default ones are used in every case.

 

[gogocar62]

Set your own ringtone in the Themes app.

 

[Rayearth]

Cannot pick a ringtone from the Sounds app inside Themes app. The selection options are limited this way.

 

[Jimnasium]

Set your own ringtone in the Themes app.

You can only set those from Xiaomi Theme Store in the app. How do you set an MP3 of your own choosing?