[HELP] how to set different sms app permanently? - Honor 6 b532

Hello, it seems that new lollipop build b532 keeps changing sms app back to default (huawei contacts) even if the new app (choms sms) is set as default in the default app menu in settings (tha app is additionally set to be 'trusted').
What's going on here??
Each time I leave my phone for a while, my default application is changed to huawei one:-/
Is there any way to set it once for all to 3rd party app?

HELP: From 5.10.1 (beta) to B532 (stable)

Hi XDA members,

I want to go back from teh new 5.10.1 to the Stable B532.
I downloaded the B532, B526, B317, and some old Betas, but no FW wold work.
It always says, that it's not compatible with my Version.
Is there any "Reverse to B532" or anything? Or how i can go back in another way.

Information:
No Root anymore
Stock Recovery
H60-L02
Bootloader Unlocked

I'm sorry for my english :)
Hope you can help.
Thx