Is this shirk? If Muslim X performs Jumuah Salah. X sees the Imam going into sujud, while X is raising from Rukū'. X thought that that tge prayer is invalid and X Should do opening takbīr again but he has social anxiety and continued. Even if Salah is not invalid, is just the intention shirk?

Ustadh AbdulAziz al-Haqqan

This seems to be very waswas or ocd which is the main problem that should be tackled. Thus don't repeat your salah because u suffer from waswas.