PowerAutomate loops slow (complex problem)

Hi,

I am attempting to automate the task of sending invoices via email using Excel Online. The goal is to trigger this process when someone updates the last row in a specific column, which contains prices. I want to use a timestamp in Excel and apply a condition that evaluates to true if the current time minus the timestamp is between 1 and 2 minutes.

To achieve this, I've set up a Power Automate flow to run every minute. Initially, it updates a row to set the timestamps. After that, it checks the entire column. However, I've encountered a problem where, after leaving it for a day or so, the flow slows down significantly, taking 3-4 hours or even days to complete.

I'm not a tech expert, but I suspect that it might be causing lag or some other issue. I tried enabling parallelism in the condition, but it didn't resolve the problem, and the flow still lags and doesn't complete as expected.

I'm looking for creative ideas on how to fix this issue or an explanation for why it's happening. One idea I had was to make the Power Automate flow skip checking every column and instead directly evaluate the "True" condition values, which typically range from 1 to 5 at most. This way, the flow could quickly execute the necessary actions, resulting in an invoice being sent to my email in PDF format. However, I'm unsure of how to implement this approach. Any suggestions or guidance would be greatly appreciated.