A family of Microsoft word processing software products for creating web, email, and print documents.
Hi JohannSwart,
Thank you so much for uploading the requested samples.
We received the sample files, and checked the issue, took time and did a couple of tests to see if we can reproduce the same issue in our environment, but the hyperlinks to bookmarks work fine on our side.
Due to this situation, I think this issue is related to Professional Plus 2019 product! We would also really love to work with you and solve your problem, but to avoid giving inconsistent information, and to make sure you get proper and expert help, please post a new question to Microsoft Q & A Community via this link: Microsoft Q & A Community. This is a channel that has Expert Engineers who focus on Office 2019 related issues, and I am sure they will focus on your question and help you out.
Thanks for your kind understanding, cooperation and patience. I hope your issue gets addressed quickly! Good luck.
Sincerely,
Edwine | Microsoft Community Moderator