(SMBX 1.4.3) Bug-report: A missing frame while layers change [SOLVED]

[Lx Xzit]

There's a new bug I discovered recently, this bug only happens on SMBX 1.4.2.
Basically, when a layer change to another one (with the effect of "no smoke" enabled) you can see an animation is lost while the layers are changed. Perhaps in this gif you can't see very well because it did not capture all the FPS, but this happens all the time:

Spoiler

Here's a test level I did: https://www.sendspace.com/file/8yi401

[Squishy Rex]

Not sure if this occurs in the other versions of 1.4, but in 1.4.2, the Mega Mushroom gets stuck in corners. Because it bounces every so often, if it does so, within the space of 1 block from a wall, it bounces up, hits the wall, and falls back to the same place it began to bounce, however, instead of continuing in the direction it has changed to, it bounces, but back towards the wall, instead of away from it. Thus it getting stuck in the corner, in a never-ending cycle.

[Lx Xzit]

I'm bumping this topic because this problem appeared again on SMBX 1.4.3. :P