Can you guys help me deduce the problem here:
1) Got an
unlocked Note 20 U, pop in the SIMBA SIM, auto roaming etc everything on - does NOT work but showing
'R'
2) Took the SIMBA SIM out, put it in Vietnam and Singapore iPhone, works well and have 4/5G lol...
3) Back to my unlocked Note 20 U,
purchased a Vietnam SIM - works and 5G works too.
So, the SIMBA SIM works on both Vietnam and Singapore iPhone, everything worked flawlessly

But, does not work on an unlocked Note 20 U?

If so, how come on 3) a Vietnam SIM works ?