Meizu MX4 - Flyme 6.2.0.0G latest

During calls - If I'm on speaker mode - I can hear the other other person but he can't hear me. If I turn off speaker and try a call on ear mode - the opposite happens (!)  - I can't hear the caller but he can hear me.

Speaker Mic works - cause on whatsapp recrodings or phone recording it works. only during speaker calls it doesn't work

Tried - Hard reset, factory reset, 'about phone' 'audio-phone' apps  to no avail.

In addition - might be related - proixmity sensor doesn't work - probably hardware issue.

tried entering EngineerMode (*#*#3646633#*#*), then Hardware Testing => Audio => Volume => Voice but I don't now what should be the results there.

so far can have phone/whatsapp calls only via earbuds...

Any ideas?

Thanks