Unknown number blocking App that really works with Ulefone Power 5?

[sarajko]

Hello,

I tryed a lot of free and not free Apps!
Non of them will block calls from
" unknown number "
They all says that they would do that, but it does not happening!

Is there any app that can do exactly that!?

I have been contacting Ulefone Support!
They sad to me, that this phone do not have option to block
" unknown numbers"!
They recommend third part App, but couldn't say Wich is working

I am sending my phone specification:

Ulefone Power 5