Thank you very much!
There was CONFIG_ANDROID_PARANOID_NETWORK=y set in Linux config. I've disabled it and recompiled the kernel and now everything is working as it should.
I don't know how I forgot it. And I've had similar problem with RK3188 kernel.

Update

• problem with Internet access solved
• some small improvements
• images for OrangePI-PLUS uploaded, please try (I don't have plus to try)
  

Warning
Uploaded images have the wrong scripts for desktop instalation (install_lxde_desktop & install_mate_desktop).
Please download desktop-scripts.tar.gz from Mega, unpack and replace the scripts in /usr/local/bin
Check that they are executable.
Sorry fo that.

Any m8 managed to get AP working???
I tried install hostapd but having driver issues.

Must i compile the hostapd from RTL site?

Cheers

@loboris for opi plus you need to patch the kernel and for u-boot make it with script.bin support it's simpler for end-user to change script.bin then to rebuild u-boot.

Thank you, I'll try that later.
For now, I've uploaded the images for OrangePI-PLUS (with u-boot built with OPI-PLUS fex).