Weird glitch when replying to quotes

[SnuggleBuggles]

If I quote a post, my cursor jumps around, especially if I have to use the delete/ backspace key. It's maddening!

I'm using Safari on a Mac.

[SnuggleBuggles]

Still having this problem. Using Firefox, not Safari.

[oneplustwo]

I thought it was me, or more specifically, my computer! Definitely a recent development. It happens when I am simply typing away or else when I hit the space bar - the cursor jumps to the line above what I'm typing and refuses to budge from that line. Frustrating!

eta: I'm using either Firefox or Safari depending on the device.

[ett]

This happens to me sometimes too! I'm using Firefox on Windows. It is maddening!