3 hours ago
2 hours ago - last edited an hour ago
You may need a replacement SIM if the Pixel 8a needs a class C/1.8 volt SIM and your SIM is an older class B/3 volt SIM.
But you won't get one before your holiday unfortunately so you may need to keep using your old phone if you still have it or another unlocked phone.
See here for previous threads in a similar vein:
If you need to contact 48 support about this then see the links in my signature below.