I have recently updated to 24.6.4.1621 in my desktop version loaded to laptop. I do not know if my problem is related to this or a previous update. The forum shows that in version 14.4.50 @lubos implemented the ability to reorder line items throughout manager. I have tried today to clone a purchase invoice and reorder the line items without success by left click on my laptop track pad. I checked other invoices, quotes and tried also within the chart of accounts to make alterations also without success. I have tried the function in other programs I use and left click works. Any suggestion?
This version would be 10 years old (the first 2 digits refer to the year). Note that the forum rules at FAQ - Manager Forum state [emphasis added by me]:
Manager advances very quickly, simplifying and adding features and capabilities. Sometimes, bugs occur with new releases. But these are usually fixed rapidly, often within minutes. So if you encounter a problem with the desktop or server editions, update Manager, even if you recently did. (The cloud edition is always up to date.) You can check the latest version at https://www.manager.io/desktop/download/ .
Also pay attention to the age of Forum postings. We generally do not close topics that might be useful to someone. So be aware that responses to old questions might be out of date. Look for the most recent replies when searching the Forum.
For every transaction type, once you have entered a second line item, the reorder arrows appear at the left side of the lines on the Edit screen:

Why would that have anything to do with Manager?
Use Manager as designed.
Thanks @Tut. I got the reorder lines as usual and left clicking on them did nothing so would not activate them so I couldn’t reorder the lines. This was across all I tried, invoices, quotes, purchase invoices, everything. To rule out a laptop issue I open other pc programs to check left click operations and all was good, so I believed issue was within manager.
I have updated the program again and all functionality has returned.
I have no idea why you keep referring to left-clicking. Re-ordering line items is a simple matter of dragging and dropping.