Commands broken

Any use of fill command is broken entirely. Using tab to auto fill the suggestions for the next part of the operation also does not work. It comes to a point where it will repeatedly request the replace command. For example, it just rotates this: [replace [replace [replace in the command.

The command I am trying to work out is /fill ~ ~ ~ ~ ~ ~ cracked_deepslate_bricks replace deepslate_bricks and it ends up showing as /fill ~ ~ ~ ~ ~ ~ cracked_deepslate_bricks [replace [replace [replace [replace [replace [replace [replace [replace. Is there something wrong with the suggestions that commands are giving? I didn't have issues doing this the last time I tried replacing block types a few months ago.