mobile data – My Galaxy J7 phone is not connecting to the Internet without WiFi anymore, anything I can test / verify to make it work?

What would be the reasons for which my Android would not connect to the Internet using the Mobile Data mode? (that open is ON)

I don’t go out much these days since there is Covid, but I’d like to have Internet once in a while and somehow the Mobile Data doesn’t seem to connect, yet I can do phone calls just fine. It’s it using the same connection for data?

I do have a data plan in good standing and it definitely worked before (last time I can say I tried was some time last summer, so about 6 months ago).

Any idea what I could try next?