Problem with Vodafone, but only in my Samsung Galaxy A70

[Tombar]

At home, I get very little or, usually, no reception with either of 2 Vodafone SIM on my Galaxy A70, but no problem with EE or Three. However, I have no problem at home with the same Vodafone SIMs in a Redmi Note 9, an old Motorola or a very old Sony Erickson.

I've spent 3 whole days on Messenger with both Vodafone and Samsung. Anyone got any ideas?