Welcome to the forum.
This is not really a stats forum. To be perfect honest, you are almost certainly better off consulting with your departmental or university stats consultants, preferably in person---while maintaining appropriate distance.
If this is part of a course, you, one would hope that the instructor might help.
A good source of help is https://stats.stackexchange.com/ which is a stats forum.
After all that, you could post code and data here and see if anyone can help. Some members definitely have the skills and knowledge to help, though probably not me.
I am not even sure what you mean by a multilevel model; it could mean several things. We probably need to see your code to get a grasp on what you are doing. For suggestions on how to do this see FAQ: How to do a minimal reproducible example ( reprex ) for beginners