Phone [Q] Am I locked to a specific carrier?

Dear guys,
I'm on E97510H-232-10 now, with stock kernel.
I've been trying to install the E97510H-EUR-XX version on my device, but any KDZ file I have tried so far (10D, 10H, 20A) aren't changing the postfix "232-10" to "EUR-XX".

I think that the 232-10 is referring to a specific carrier's mcc-mnc (austrian), and my device is locked to that exact carrier. However I am using my phone on hungarian telenor (216-01), therefore there are some kind of incompatibles with my network (which causing massive battery drain).

After doing some FreeGee, my fastboot menu says that the phone is unlocked (and of course I bought it unlocked and carrier-free). If I now try to install kdz either with kdz updater, or stock LG pc suite, the software is installing as normal, but my postfix "232-10" is staying every time the same...

I've been researching on forums for the past 2 weeks, and for now I am so tired about that sh**.
Could you please tell me:
  • Which KDZ file to flash (size too please)
  • What is the proper method to install (a step-by step guide would be sooooo useful)

Please help me