New problems with signal 5g mi 11 lite 5g ne on 14.0.6

[CHRITECH]

Good evening dear group, I have a small problem with the latest version of xiaomi.eu for the xiaomi mi 11 lite 5g ne and it is that to try some things I decided to return to stock and I realized how noticeably the coverage in the global rom 5g was much better, when I returned to xiaomi.eu in the same position where in the global rom I had 5g I only got 4g and in areas with 100% 5g coverage I only got 4g, I was only able to connect to the 5g network on occasions, I thought It was a problem with my sim but I tried another 5g device and I did get good coverage. do you know what it could be?