OwnCloud issue: SSL certificate has expired

[fmnap]

Hi there, I installed OwnCloud through the app center and am able to log-in and create users. However, whether I try to access the store through the OwnCloud GUI, I get the following error message:

No marketplace connection: cURL error 60: SSL certificate problem: certificate has expired

I had previously created a valid server SSL certificate with let's encrypt that's active for another 3 months, visible in the "myQNAPcloud" under "SSL certificate" - what am I missing?

Also, when trying to log into OwnCloud through the android app and the server ip address:port, I get a similar error message "SSL initialization failed", I guess that's related..

Would appreciate any help!