Issue with copy and pasting spreadsheet lines from hosted legacy app in AVD

Activating the "try the new client (preview)" option in AVD creates an issue with copy and pasting spreadsheet lines to Excel.

It's copied from a legacy application hosted in AVD that contains spreadsheets.

As you can see using the old client it works like expected; it pastes all the lines appropriately into multiple rows.

In the new client however the lines get copied into only one row instead.

The application is hosted on the same server in both examples, the only difference is the client feature.