Dialer behaviour in conflict with Google Play Services

Hi guys. This is the situation: I have a zeblaze blitz.
When answering or making a call, most of the time I can’t hear anything, while the other person can hear me.
I need to exit and re-enter the dialer and go back to the call to have a normal conversation.
After little time this bug is getting really annoying, if you use the smartwatch to call. So past days I was searching for some workaround, with no luck.
I just noticed that this doesn’t happen after I uninstall Play Services, so it needs to be some conflict. But it is not a solution, since you need Services basically for everything.

Can I know if this is a common issue for blitz users, and also maybe for other smartwatches too? 
Have someone found a solution already?

It’s a known issue for all the 5.1 round watches and you’ll need to wait for an OTA.

Well, that could be a problem for 2 main reasons:
zeblaze is claiming there will be the update “next week” for two months, I’m not hoping to see it soon anymore
I have twrp and a custom rom installed, so my ota updates are broken.

Said that, assuming that zeblaze will surprise us with a real ota update, how should I get it?
Would it be safe to flash it as descripted in the stock rom section? In that case I would lose twrp, wouldnt I?
Or maybe someone here will make a twrp flshable rom with the new firmware? That would be awesome.

I received this reply from Zeblaze yesterday, “Dear customer,Now, V06 is the latest one, they are making the newer one, but need about 15–25 days, because solving the iOS problem.”

They are not to be trusted. If you go on their facebook page, you can find how they are postponing the release date since August.
Now it’s so stupid that they are delaying for another month. If the only problem is the ios compatibility, they could release this update now and then continue to work on that issue for next update.

on there Facebook page they said ota was coming out on the 28th,that has now been and gone