Request error message when open ecp from Edge Chromium or Google Chrom

Hi friends,

we use Exchange 2016 CU 18. When i try to open the ecp in Edge Chormium or Google Chrom i see the following error message: Your request couldn't be completed. Please try again in a few minutes.

It seems that all works properly.

When i open the ecp via Internet Explorer 11 or Firefox this error message will not shown.

Is this known issue or may am i the only one who has this?

The message will also be shown when i add ExchClientVer=15 to my URL string.

Do you have any idea or tipps what happens here?

Best regards

Sebastian