No status change after payment

When I installed payment reference, the module worked as expected. After a payment, I closed the window (text (copied from the coding):

Your payment is %status. You can now <span class="paymentreference-window-close">close this window

and I went back to the orininal browser tab. There the text

<a href="@url" target="_blank">Add a new payment</a> (opens in a new window

was changed into:

<a href="@url" target="_blank">View payment details</a> (opens in a new window)'

Suddenly the last step didn't function anymore. After paying, the text is still mentioning: 'Add a new payment' .

I already tried the following:
- deïnstalled modules with hook into payment
- deïnstalled translations
- flushed chaches (many times!).

Nothing helped.

I suppose this is a bug and I can help to find it if you give a suggestion what I have to investigate.