Lag spikes due to debug function triggered when pressing 'A', 'S', 'T', ... while having Debug screen open

There seems to be some kind of "state" in which some actions will cause chunks to be reloaded and/or a sudden drop to 0 fps and back up (lag spike). For a while I was just flying around in the nether getting frustrated at what seemed like random lag spikes. After I figured out that it wasn't random, I experimented with this for a while and reloaded the chunks. I didn't have the same issue after this.

Actions that cause this:

• Opening chat (T)
• Walking backwards (S)
• Strafing left (A) (This only caused a chunk reload for me.)
• Flying into the world border in the nether. (Not sure if this causes a lag spike directly.)

Known Temporary Fixes:

• Manually reload chunks (F3+A)

To Reproduce this issue:

• Create a new world in single player with creative mode.
• Press F3.
• Try doing the actions listed above.