Quote units are lost after copying


I’ve just installed your Invoiceplane v 1.5.9.
I’ve created quote with values and units. And after copying this quote via TOP right menu button (copy quote) I get that all Product Units are lost.
Also when copying that quote for another customer NOTES are lost too.

Where should upgrade code to fix that bug?

I’ve read all your manuals but there’s very old information and there’s nothing about quotes with solution.

Thank you.