Bonjour won't find network printer

Hi

Since a while, Bonjour can't find my network printer anymore. If I enter the IP address, the printer will be found and I can check properties etc. But I can not print anything. I have a second iMac in the network which seems to have no problems printing. I've tried to remove and add the printer, but that doesn't solve the problem. Reinstalling the printerdriver doesn't change anything either. This all started a while back, maybe since 10.11.4. I have been running the latest beta versions since they became available, but have no clue if this related to the beta versions or something else.

Stupid thing is, I've had the problem years ago. When there were no public betas. But I have no clue how I solved the problem back then.

Please help