B1 (EARFCN 300) invisible for my Chateau LTE12, ok with R11e-LTE6

I’ve an issue regarding my Chateau LTE12.
The modem EG12-EA seems to be unable to connect to B1 EARFCN 300 with italian LTE operator TIM. Even with “cell monitor” is invisible.
Other B1 EARFCNs are ok (525 Vodafone Italia, 150 Wind3, for example).
R11e-LTE6 (same BTS, SIM and operator) connects with B1 EARFCN 300 without any issue.

Firmware:
Modem: EG12EAPAR01A10M4G
RouterOS: 7.1.2

Any hints? Any incompatibilities?
Thank you.

AT+QENG="neighbourcell"

with Vodafone IT (B1 EARFCN 525):

  output: +QENG: "neighbourcell intra","LTE",525,183,-13,-111,-79,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",525,15,-20,-121,-89,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",525,468,-20,-120,
          -89,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",525,39,-20,-118,-90,0,-,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,199,-15,-113,-90,0,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,
          238,-19,-116,-89,0,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,430,-18,-117,-89,0,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,474,-20,-119,-89,0,-,-,-,- +QENG: "neighbourcell inter",
          "LTE",1850,36,-20,-119,-88,0,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,37,-20,-119,-88,0,-,-,-,- +QENG: "neighbourcell inter","LTE",1850,339,-20,-118,-88,0,-,-,-,- +QENG: 
          "neighbourcell inter","LTE",1850,364,-20,-119,-90,0,-,-,-,- +QENG: "neighbourcell inter","LTE",3025,64,-8,-117,-100,0,-,-,-,- OK

so B1 functionality seems to be ok (EARFCN 525 in this case, but works also for EARFCN 150).

AT+QENG="neighbourcell"

with TIM IT (no B1 EARFCN 300 shown, only B3 and B20, verified by other modems):

output: +QENG: "neighbourcell intra","LTE",1350,497,-15,-117,-78,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",1350,20,-19,-119,-89,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",1350,254,-20,-121,
          -89,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",1350,342,-20,-121,-88,0,-,-,-,-,- +QENG: "neighbourcell intra","LTE",1350,4,-20,-121,-88,0,-,-,-,-,- +QENG: "neighbourcell inter","LTE",
          6300,202,-15,-106,-84,0,-,-,-,- +QENG: "neighbourcell inter","LTE",6300,132,-20,-111,-82,0,-,-,-,- +QENG: "neighbourcell inter","LTE",6300,484,-20,-113,-83,0,-,-,-,- +QENG: "neighbourcell 
          inter","LTE",6300,1,-18,-114,-83,0,-,-,-,- +QENG: "neighbourcell inter","LTE",6300,374,-16,-106,-82,0,-,-,-,- +QENG: "neighbourcell inter","LTE",6300,459,-18,-111,-82,0,-,-,-,- OK

If I try to lock only B1, in general, there’s no connection at all with EG12-EA and the result of AT+QENG="neighbourcell" is only:

output: OK

B1 cell-ID 242 and 240 received by another modem (R11e-LTE6 Mikrotik), same BTS, SIM and operator:
2d588471c8af325654aa51bbd91142688c1b0804.png
so B1 EARFCN 300 (PHY Cell ID 242) exist ad it is operational for that BTS.