Decimal Prices not possible

Hello,
we have massive problems in the store since the last update with the prices and all information that have a comma / period (decimal numbers).

If we deactivate the plugin in staging, then everything goes so far, if we activate it in the last version, then we have massive problems when editing.

Price Display/Price Entry:
Quick Edit does not work properly (it deletes every comma).
Display on the product pages is wrong (comma/point)
Invoice editing incorrect
Stock keeping incorrect

We can specify it on the Curency Plugin, because in staging after deactivation the edit and comma/dot on price goes again.

Is there any possibility to rollback? Where can we get the old versions?
Also we need a fix for new Version, please.

Thank you