nvidia gtx 980 ti, driver problem?

Hi all,

i have a mac pro 5.1 mid 2012, osx 10.13.6, and a nvidia gtx 980 ti.

Until now, three days ago, the video card worked perfect. But from one day to another the webdriver refused to work, and the vid card only uses a generix osx build in driver. Slow and flickering.

I opened the control panel, clicked onto the nvidia driver manager icon. osx told me thet the control panel must be restarted to work. Did it, same result.

Then i downloaded the WebDriver-387.10.10.10.40.140.pkg from nvidia and from macvidcards, to make a complete reinstall of the driver. Both told me that i cannot install, only choices are abort and move to trash. No help from the apple security control, no extra priviledges possible.

When booting to boot camp with windows 10, the video card is still working perfectly. So the cards health should be ok.

Meanwhile i have installed the good (ahem, yes) old 5770 for flicker free screen.

So my question is...

Did Apple revoke the digital signature of the driver? Do you have any hints where i can get a working driver?

macvidcards and nvidia still didnt answer.

System is mac pro 5.1, osx 10.13.6.

greetings from germany

Chris