Usually it is the sleep comfort and leisure comfort causing this issue. Check that the bed room has a positive sleep comfort and the Kitchen has a positive leisure comfort.

If either of these are negative it will eventually lead to big comfort debuffs. Work comfort will always be a little negative, so it needs to be balanced out by the sleep and leisure comfort.

Also as an additional note, the med beds have a tiny negative comfort on sleep, but if they are put in an area where there is more adding to the negative comfort this could also be a big issue for the crew's mental health. Aim to put medical beds in their own space and keep it at the minimum negative. So that when they are used it will not cause big debuffs.