Same here i bought the aircraft yesterday and installed in FS2020. I managed to fix it by moving the aircraft folder from the “packagescontent” folder which would have been installed in the community folder into the community folder directly. The packagescontent folder is useless so just move the a350 folder outside of it.
you may also experience another issue in-game which is engines thrust does not exceed 1% when starting up. Not sure if this is got to do with the faulty installation procedure or not- i did not find a solution for it yet.