There are two Discords you can connect to to talk about Hexcells:

https://discord.gg/VEqFbqc - Puzzle General; this is a place for general puzzle game discussion.

https://discord.gg/dnvVNDR - r/hexcells; this is a place for Hexcells discussion. It is NOT a dedicated server for the speedrunning community.

If you have any questions about either of these Discord servers, feel free to ask a moderator!