Allan K

Are you sure that your speakers or sound card was working properly? I've had a friend playing Minecraft whose sound card or driver failed often which required a restart or re-enabling of some sort.

It's crazy, I know, but Minecraft does suffer from memory leaks.

The best course of action you can take at present would be restarting the game after the 20th time you've switched maps. Or, assuming that you are trying to transfer something from Creative to Survival, take photos of whatever you've built so you don't have to swap the maps so much.

I frankly think this will be a tough one to solve, as this (plus the other memory leaks) have not been resolved for a while now.

I assume by the above that you are describing the "running bug" situation. Running takes exactly two W key presses in short succession (e.g. in a second), and on the second press one must hold it for the duration of the run. Doing just one or more press right after will not make you run any faster; instead, it will cause you to either get stuck in a walk-run loop or in more recent versions will just make you revert to walking.
Perhaps a "run cooldown" may be implemented where after two presses in a second the game treats subsequent presses separated by less than one second as a continuation of the run, or otherwise ignores them for a second. The former is more ideal for escape situations; at the same time it may be less than ideal for situations where correct positioning is a priority.