The Mieterverband offers legal advice, free for members, discounted for non-members. This is probably more affordable that going through your legal insurance, if it has a meaningful deductible.

More broadly, they offer other housing-specific services to members.

For example, if you are worried that a landlord will try to misrepresent damages during a handover, the Mieterverband will (for a fee) send out an agent to assist. For example, there is a schedule of costs that a landlord is allowed to charge for damage, depending on the type and age of the wall/floor/whatnot. Anybody can download this schedule from the MV website, but the agent would have experience in making sure that it is correctly interpreted.