That’s correct. If you’re just starting a new transaction and not trying to link any async work that originates from that point, then you won’t need to link it.
However, if there is an existing Transaction, then the dispatcher=true would get ignored and that span would be associated with whatever existing Transaction it is on. Were you able to confirm if there is an existing non-web Transaction that is picking up this work ? It’s easy to miss, so just double checking. On the Transactions page show either All Transactions or non-web and see if it’s getting picked up there. If you want, shoot me a link to the app and I can take a look to see what all might be going on. I can see some metrics that may be useful for troubleshooting.