Thanks @v-xida-msft for your aswer and tips.
Here the answers of your questions:
Do you mean you could not share your custom connector to your end users?
Yes
Further, which PowerApps license do you own for your account? PowerApps Community Plan?
I have PowerApps Plan 2
I tested the same as you. I made a Custom Connector and yes I can share the Connector.
I tested a old Custom Connector and yes, I can share the Connector with user.
The Custom Connector that I build yesterday is still in trouble and cannot shared.
This Connector is created Yesterday by me but there is no owner
This Connector is created 3 months ago and I'am the owner and can share the connector with users