This may be a problem with all TP plugins. Jon has found the same problem with Ocpn_Draw, and I believe has fixed it. It has something to do with the way OpenGL is implemented in MacOS and perhaps changes in to
OpenCPN libs.
I have not followed this closely, and will not be fixing this for awhile, busy with the Manual.
Thank you for reporting this though, with your OS and version numbers.
LATER
By the way, this is very very old
Open CPN version 5.5.2
You should update first and your plugins, the problem may disapear.