We’ve received a few more reports of this issue overnight @Anita_Blanchard. There is a Google Docs update of a link insertion dialog that is being gradually rolled out. As you pointed out, the same thing happened in 2021 and it took a few days to address.The team is working on a fix and we will keep you updated.
In the meantime, the Google Docs sidebar add-on is working normally and can be used as an alternative for inserting citations.