e-SIM conversion failure

Been trying to convert my physical SIM to an e-SIM in iPhone 13.

Chose the correct pathway, used friend’s hotspot for WiFi> my phone showed it was converting, but it never concluded- just stayed on the in-progress field.

Phone settings did populate e-SIM details but connection lost and phone stopped working.

Had to get a replacement physical SIM and delete e-SIM before iPhone worked again.

Curiously, was using friend’s hotspot to do the conversion…his iPhone stopped working altogether as well. He took SIM out and in again before his own phone would work again.

Any ideas /advice appreciated