Hello @alyaksander welcome to the Local Guides Connect community.
For all reviews and uploaded media, a filter checks not only checks for violations of the rules (I like your “not willingly, at least” - many others forget this point), but also to protect against SPAM and - more importantly - against false information. This is just guesswork and the can be many false positives, because when in doubt the post will refused, i.e. hidden to the public and unless you submit an appeal, there is no human operator involved (as of our knowledge).
Furthermore, if photos or videos are attached to review and only one of those media is refused, the entire review including all media will be hidden. So, the first step trying to fix this situation would be to remove the media and see of text-only is published and if so, add the photos again one by one. Videos is yet a bit different, since the approval can take more than a day.
Not at all! The reason is, if Google would reveal what exactly they found, it would make the “work” for spammers easier.
I suggest this series articles for some more hints: How to Get In and Out of Trouble: The Main post
One more thing:
If you want some help from other local guides in this forum, it would be helpful if you set your profile public, so we can see what you did post and how many of your posts are hidden.
Hope, this helps.