Personal hotspot and Kindle

Does anyone know why Kindles have stopped finding the personal hotspot from Apple. I have an older IPad Pro, IPhone XR and IPhone 11. Kindle Paperwhite and Oasis will not even show that hotspot. When you do it manually says cannot connect.

Seen post about maximising compatibility on hotspot, but that option is not available, may have been in the past.

Bluetooth does not work either as Kindle appears to be looking for an audio device only.

Hotel WiFi does not work as the Kindle connection thing is hopeless- hotels want you to put in room numbers , email address etc, not something the Kindle browser even considers.

thanks