What should I do if the previous property refuses to hand over the new property on the grounds that some owners are in arrears with management fees?

Then let the owner pay the relevant fees. There is no reason to refuse to pay the property fee. But if you are not satisfied with the property, you can complain to the local housing management department and ask the property to rectify within a time limit.

Of course. As an industry practice, and also for the smooth handover, the original property company, the residential property company and the industry committee will negotiate, and the residential property company will first supply the property fees owed by the owners to the original property company, and then the industry committee will notarize them to ensure that the residential property company will coordinate to recover the property fees owed by the owners. At the same time, the original property company and the settled property company should do a good job of handover.