The game works great, but for some reason, the total game timer resets to 0:00:00 randomly and sometimes it freezes in that value a while before starting again. Is someone having this issue?

Yep, it's the same on my end. I haven't the slightest idea why this is.
It doesn't bother me too much though.

It doesn't bothers me too (I can just stick with Galaxy's timer), but is so weird that a basic feature like that wasn't working correctly. Oh well. Thanks for the reply.

After some research, found that the Steam version had this same issue after game's release, didn't find if it was fixed though...

I noticed another issue and it must related to the main timer issue. While playing Vert's route, I remember grinding a bit (~30 min or more) on her first dungeon as a leader (she was alone and couldn't change her). While checking Vert's challenge "Leave it to me!" (Spend X time exploring a dungeon as a leader) her time was just 22 sec... Even ifi I was more than half an hour!

So I did a little test. I set her as a leader and let her standing in a dungeon doing nothing for 2 minutes (without entering a battle) and the timer was frozen at 22 sec.

While it isn't game breaking (again) and completing the challenges doesn't gives you stat boosts like Re;Birth 3 or the original Megadimension VII, it's a bit annoying to not be able to complete these challenges correctly... :(

EDIT: Nevermid it it seems to work fine, the time moves when the character walks and stops when you stay still...

wow it's 2023 now and this bug with the resetting time is still in the steam or gog version.