Version 0.0.36 from F-Droid is now affected too.

It is a Vulcan salute: https://en.m.wikipedia.org/wiki/Vulcan_salute

I don’t recall why Riker would have been using one in that context, though, unless TNG was trying to establish the gesture had expanded in use across the Federation.

EDIT: also, this is in S01E15 “11001001”, not E14.