This was fixed for Steam client (https://github.com/ValveSoftware/steam-for-linux/issues/600) but not for TF2
This was a bug in some SDL code I wrote. Will be fixed in the next tf2 update. Thanks.
Today TF2 updated but cursor still looks to the right
This was fixed for Steam client (https://github.com/ValveSoftware/steam-for-linux/issues/600) but not for TF2