Fish: version 3.7.1-1593-g5b324f8ec (Notably includes: d51f669, addressing cursor placement issues)
OS: Arch Linux
Term: Kitty

cd ~/Random
# press: `esc v b d` to delete `Random`
cd ~/[CURSOR] # this is incorrect, cursor should be on the slash
# press: `a` to attempt to enter insert mode after the current cursor
cd ~/b # example of b is the first character of the insert

This example uses visual mode d to delete some words, moving the cursor backwards, then a to try to move into insert mode, which causes two issues:

1. The cursor is misplaced (should be at the slash, in accordance with real vim)
2. The first character of completion gets inserted incorrectly.

I believe the actual issue here is the placement of the cursor the wrong place after the delete, similar to other issues d51f669 has fixed. Because of this, the a is considered used to take the autocomplete character.

If you move the cursor back to the slash correctly first, then press a, this behavior doesn't occur - but I'm not sure if just doing so would fully fix the issue, because moving the cursor like that also removes the autocomplete suggestion.