@ggiannou This issue is resolved in the latest github version of theme https://github.com/puikinsh/Shapely
Also alternatively you can use the solution posted in the following topics to resolve the issue.
https://colorlibsupport.com/t/add-clients-widget-broken-double-page-titles/page/2/
https://colorlibsupport.com/t/error-after-activate/