I have experienced this and reasons could be many :
-->Certificate on IAAS
-->Memory crunch
Finally issue with BP which was configured, but some reason it's configurations are not fully utilized.
If you create a new BP that should work, with me earlier creating new BP worked good
However try to run below command :
Vcac-Config.exe RegisterCatalogTypesAsync -v
This will register the catalog items.
NOTE:
Please take a back up/snapshot before you do anything
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regards
Gayathri