Hi @MG_User ,
Could you please show the expression in Condition?
If you're having trouble checking current inventory are less than 10% of initial inventory, please provide outputs from the current inventory and original inventory in List rows in a table and I'll provide you with a solution.
I recommend you try Filter array and Create HTML table.
Then insert the HTML table in email body. The HTML table contains items that are less than 10% of initial inventory.
Your current flow will send email for each item that is less than 10% of initial inventory.

Best regards,
Rimmon