Cannot switch call from phone to Samsung Galaxy 4 Classic watch

Hola,

I can transfer a call from my Galaxy 4 Classic watch to my OnePlus 9 phone but cannot transfer in the other direction (from phone to watch). Pressing the option that supposedly does that has no effect. This used to work, although it might have been on my OnePlus 6 (same watch). I cannot remember if this problem started when I got the new phone or if it initially worked on the new phone. I have tried resetting the watch.

Gracias.