That’s the game version that tower unite installs itself as by default.
Basically all files are packed into one single file in a way that heavily increases loading speed.
So if you want to decrease loading times you can always head back into the beta section in the library properties and set it to “dont participating in any betas”.
Based on what kind of hardware you got, and that tower unite is running on an ssd while your game version is set to “lowbandwidth” then the expected time to join the plaza servers should be around 40 seconds to 1 minute at most.
Since the loading time is 5 minute it seems likely that some game files have become corrupted which could cause a high computer workload based on what files it is that have become corrupted, or your computer is just generally under a high workload.
Based on my own experience the 0 fps for 1 second thing is normal, i have tested HDD with PAK, HDD without PAK, SSD with PAK and SSD without PAK and it seems that on all of these variations there was a very short delay when you had just spawned in the plaza before you could actively hear in game sounds and gained control of your character.
Said delay was noticeably shorter when it’s running on an ssd.