So, if you have multiple sites on the same Cloudflare account, the UI gets screwy when editing workers.
For example, if you have a worker script on domain A and domain B:
Open the worker on domain A and make a change, but don’t save it.
Now go back to the dashboard and open the worker on domain B.
The change you made on domain A is shown here.
Go back to the dashboard, into Domain A and save the change. Now go back into domain B and it shows the original (unchanged) worker.
I suspect any changes to the worker are being cached in your session (so you don’t lose them if you back out of the page) but it’s not storing the domain the worker script belongs to, so when you switch domains the cached worker script persists.