did you simply refresh chrome or did you try restarting it altogether?
it could also be that the file is not supported (csp and medibang files are not for ex) or the file may still be too large for webtoon/tapas after slicing - they have limits like 2mb on webtoon for ex.
you can always try using the original croppy to slice.
unfortunately husband and i will not have the time right now to fix bugs, we just had a baby and are a bit busy.