@Sebastian Kuhn - If you have set the board's Share settings to Anyone with the link to Can edit, than anyone with a modern browser should be able to access and edit the board, e.g.:

If you have the option with the globe icon set (the one beside the "Set password"), then it should be working.

There was another report of this not working recently in this post.

I would suggest that open a ticket with Miro support. Here’s the link to the support form: Submit a request – Miro Support & Help Center.

Thanks for the hint. request is sent. 

It may be an issue with the internal infrastructure. VPN issue… Any ways known how to solve that?

Thx

@Sebastian Kuhn - When you mention VPN, are you referring to your customer and that they are using a VPN? If so, I suppose that could cause an issue. I use one VPN for work and another for personal and they work fine. If your clients are all trying to access the internet/Miro via the same conditions, i.e., through the same VPN, they will likely need to involve someone from their IT department to help troubleshoot the issue.

@Sebastian Kuhn - From the test you and I did--sharing a board with each other that was in in Anyone with the link → Can edit, it appears that the issue is likely on your customer’s end as they cannot load the boards through their VPN. They should reach out to their IT support team for assistance.

I would also suggest that you update your Miro support ticket with these new details - you should be able to reply to the confirmation email Miro support would have sent. You should also be able to get to your ticket list using this link → https://help.miro.com/hc/en-us/requests