I don't believe this is a bug. I just checked the wiki and here is a caption from the Behavior section:
Note that even with commands, effects cannot be made to last forever. If an effect is set to an excessively large amount of time, such as 182 hours [655200 seconds], it will display as "*:*", but will still continue ticking down and eventually expire.
I believe this is implemented just to show that the timer is very high and may never be reached.
Also, change the keybind for Discord aswell.
Very anoying for trying to write relative coordinates in command blocks.
Same happened with me, only it was random based. Thanks for the fix.
Odd, some clients crash because of clicking on the language settings. The resulting error is because the client couldn't find K (I believe it's Russian). Not too sure if they are the same bug.