Basically it it just lagging behind by one frame.


STEPS TO REPRODUCE
1. Make 3+ frames
2. Draw on the frames
3. Play the animation

OBSERVED RESULT
In one document, it worked properly and did not lag, I duplicated it except in CMYK instead of RGB and it did not work. the other 4 did not work, they lagged, they were all either in CMYK or RGB. I don't know why that would effect anything but just thought I'd mention it. When I would press play, they did exactly what I expected (aside from the first one) by lagging behind by one frame. I would press the play button and it would play, but then once it hit frame 2 it would not change. Once it hit frame 3, it changed to Frame 2.

EXPECTED RESULT
Exactly what happened above ^^^

SOFTWARE/OS VERSIONS
MacBook Pro (Retina, 13-inch, Early 2015)
Processor: 2.7 GHz Intel Core i5
Memory: 8 GB 1867 MHz DDR3
Startup Disk: Macintosh HD
Graphics: Intel Iris Graphics 6100 1536 MB

ADDITIONAL INFORMATION
I'm not entirely sure what happened with the first recreation, as it worked perfectly fine, the rest, however, didn't. Once I render the animation, it plays perfectly fine, it's just in the program that it has this 1 frame behind issue. I have gone to the chatroom and they tried to help me as best as they could, but nothing worked, I have also looked through the forums and found the exact same problem which was fixed by changing the cache storage backend, but that didn't work for me either.