I upgraded to 4.6.10 a few days ago and someone has asked this on my site today, I don't have any Samsung device to test it on though.

The Samsung Internet browser is based on Chromium (the same browser engine as Chrome), so it should work fine if they’re using the latest version. Would you be able to find out what version of Samsung Internet, and what device, they’re using?

I am not seeing any issues when using either quote selection or full quote on that browser. There was however an update to that browser which fixes an issue with the keyboard, which sounds very similar to the issue they are having. So it would be worth asking.