Note 4 n910 modem problem

Hi my name is Roy and im from the Netherlands.
I bought my phone from hungary because the n910C version didnt come to my country.

I have had a bad signal on the 5.0.1 version and i tryed all modems below.
Now on the 5.1.1 version i still have a bad signal and cant even make phonecalls inside my house.

i installed the hungary version of the 5.1.1 version. Could it help to use the Poland version?

i have tryed this modems already:

MODEMS Voor 5.0.1

BOB4 Modem
BOC3 Modem
BOD1 Modem
BOE1 Modem
BOE3 Modem

MODEMS Voor 4.4.4

ANJ8 Modem
ANK5 Modem
ANK6 Modem
ANL2 Modem
ANL3 Modem
ANL4 Modem
AOB1 Modem