Jade Wang from Google posted in the Google Business Help forum an FAQs on what to do if you are having technical issues with your Google Maps reviews.
She answers 11 different questions related to this topic. Here are the questions, but if you want the answers, check the Google Business Help forum thread.
1. Where did my reviews go?
2. How do I know which of the above reasons is affecting my listing?
3. How do I get them back on my listing?
4. Where are my owner responses?
5. That review is clearly fake, written by an ex-employee, etc. — how can I get it removed from my listing?
6. Why are the reviews on my listing not related to my business?
7. One of the links in “Reviews from around the web” is wrong — it’s going to a page of reviews about an unrelated business. How do I get rid of it?
8. Why can’t my customer leave a review?
9. How can I report inappropriate/spammy reviews?
10. I’ve reported a review on my listing, but it’s still there. Why won’t you remove it?
11. But none of these questions address the issue I’m experiencing?
Forum discussion at Google Business Help.