Microsoftniranfreeman unfortunately by design there is no channel to reconmect them from the Azure Portal. If this is your question.
Me too find it hard to reconmect them at scale, e.g. after internet outage, or network issues.
Sometimes changes / updates on the Arc Agent also prevent the simple reconmection as they changed certs. So you would need to update the agent first to latest monthly. In this case it's easier to remove and install the agent while also removing the Arc object.
Then if the agent was offline for too long the connection will be invalid.
In general the workflow is clunky as removing the object also break things, like Tags etc. So at the end of the day you would like to automate this process via PowerShell*.
I hope that the Auto-updater for Arc will improve things a lot. Esp updating offline Arc Agents and try reconnect them automatically.
*There is a PowerShell Module for Arc by Microsoft, aswell an improved one by MVP colleague Kaido Järvemets you can find though his blog.
