Bonjour sync iPadPro and MacBooc Pro

I have problems syncing with bonjour in a local Network. I have set up the bonjour service as described in the help section. And my databases (Mac) were shown in the menu (iPad). Syncing began after I had chosen a database. Then syncing stopped with the message like “MacBook Pro offline” this is not true , the Mac is on, online and still in the same net. Any hints what can be done?

Have You carry out the sync in the same workflow as I decribed in DTTG 2.1.6 und DTPO 2.9.12 Synchronistation?
Greetings from Germany.