Google has suspended accepting and posting reviews and Q&A on local businesses during the coronavirus (COVID-19) outbreak. Google posted in its help document "New reviews, review replies, and new Q&A will be unavailable during this time."
If you try to post a review, you get a message that reads that this is unavailable. Here is what Jason Brown shared on Twitter:
Joy Hawkins from the Local Search Forums said "In the meantime, I would suggest not asking people to leave reviews until it starts working again. We'll let you know when we hear back."
Forum discussion at Twitter and Local Search Forums.