I made a post about this same issue roughly 1 Year ago:
This issue was resolved originally but has come back slowly over time, with these past few days being at its peak slowness.
It’s taking at least a few hours for our Quickbooks Invoices to Trigger the Zap.
Seems like it’s triggering in bursts of many invoices at once:

This Zap is using an instant trigger, so it should be triggering immediately after an invoice is saved. That is not happening.

Eventually, all Invoices will eventually come through to Zapier, in bursts, as I described. But the time it takes for that to happen is far too long.
1 Year ago when this was originally fixed, it was working great immediately after the fix and has slowly degraded again to the point where it is as bad or worse than it was prior to the fix.
Hoping that Quickbooks can be contacted again regarding this via Zapier so that they may patch it.
I’ll be switching to Zoho Books / n8n for at least this workflow in the next 60 days as the quality of service is just not up to par for what I need it to be.
But in the meantime, if this can be fixed, that would be great as its slowing down my staff significantly.



