I know if you restart a level in Sonic 1 2013 you start from your previous checkpoint. But if you switch levels weird things happen.

Here's an example from my current World Record in Marble Zone Act 1 with the glitch.

I start in Green Hill Zone Act 3 and I reach the first checkpoint in 4.85 seconds (4 frames from my best), I restart the stage to start the same stage from the checkpoint. (Is this intended)

From this checkpoint which I reached in 4 seconds I go to the next checkpoint (technically the third checkpoint because I skip the one at the top) in GHZ3 which I reach in 6.56 seconds (1 frame from my best)

Now I switch from GHZ3 to Marble Zone Act 1 just before the sign post and I finish the stage in record time, clocking in at 6.25 seconds of IGT

Obviously the third room was glitched but did the first checkpoint work as intended?

Also yeah my video has a lot of pauses because I was pause buffering many frame perfect inputs to go as fast as I did