TL-WR842ND V2.1 - TX-power not working properly

First of all, please, for the love of god, stop saying tx power doesen't matter, it does, a lot, and for those that use openwrt, I expected to see what open source software meant to a lot of us in this forum and discussions, the power in our hands, to make what we want of our hardware, with no limitations and restrictions arbitrarily imposed upon us, to help each other in acheiving that, but saddly, the majority of discussions regarding tx-power doesen't seem to reflect that. obs: I'am brazilian and will use my router in this county, better get that out of the way before more acusations are made.

To the community, sorry for that, but I needed to vent, now getting to the good stuff.

I installed openwrt today in my router, a TL-WR842ND V2.1, is my first time doing that, and I got to admit, now I get when I read that you can turn a 15$ router into a 100$ one, openwrt is amazing, and I hope someday I will be able to help maintain it.

The issue, when leaving the router on deafault (it was bought in the US, if that makes a difference) max power acording to iw phy is 21dbm, and set to 20dbm, reporting back 20dbm on iwinfo - If set manually to 21dbm, it reports back 21 dbm - if I change to brazil, my maximum power is now 20dbm (I mean, what? our regulations limit it at 30dbm) but when trying to set that it allways reports back at 16dbm - and if I go back to US, and try to set 21, it reports a maximum of 17dbm.

If anyone can help, I will greatly appreciate it, unfortunately I will have to try same hacks to unlock power because of this problem, but I hope that this can be solved

just for those curious: I will be using this router in a rural seting, with no networks arround.

edit: just found this, https://forum.archive.openwrt.org/viewtopic.php?id=44916, seems like this router is capable of 27dbm, and would run fine on that power setting, sad that I can't make that work by simply putting my country in the settings anymore

edit2: found this, https://bugs.openwrt.org/index.php?do=details&task_id=1861, it is exacly what happens to me