The Stall counts do not seem to show any details under Traces / Errors.
We need to understand what/where the stalls actually are.
Release : 10.7.0
Component : APM Agents
A stall is just a transaction that takes over 30 seconds to complete, if the transaction normally would take longer than that, it would still be counted as a stall.
So it is not necessary for there to be an error reported with the stall. If an exception is also detected as part of that transaction, it would appear as an error.
So the same stalled transaction could increment the stall count or both stall and error count.
It just might be in practice that most stalled transactions also report an error. but it also relies on it being an exception that can be detected by the agent.
There should be an automatic transaction trace taken also as part of the error which might give more information into the error, at least the corresponding trace might identify another slow component in the transaction.
Note from the docs:
"When the error is a stall, the error message is Stalled Transaction."