Dimitar found an issue where you get an error message and are unable to delete a sandbox while other sandboxes are being created asynchronously. The error message is shown below.
I believe the problem is because the http request object that we use to send a sandbox deletion request to another app is single threaded.
I made the fix.
The fix had to be improved as some tests were failing.
Merged the fix into develop branch and verified that it works ok in the test environment. Will move fix to prod later today.
Deployed the fix to production and verified that it works.