There was an issue with vCenter 6.7 U3h where the applmgmt service timeout settings needed to be increased to 600 seconds in order for the service to start...
https://www.provirtualzone.com/after-updating-vcsa-to-6-7-u3h-applmgmt-service-did-not-start/
Has this issue been resolved in vCenter 6.7 U3i?