Post a pic of the rail. (and measurements) I have a jar of useful bits I have saved from the past, might just have them.
I have been having problems with voiles too. Went to buy a pair of nets for a friend.
Boyes didn't have prepacked ones but had samples hanging up, labelled 72" 183cm.
For some reason I decided that was a panel, 72" and 183cm wide (yes, I know 183cm =72")
Reported back, now convinced I am looking for 2x66cm wide panels. Since it is a picture window, I should think, no, 66" but... realised it was
not a panel but a sample. Decided to buy whole half metres, so asked for 1.5m there were a few cm left over on the roll, so she gave me the piece. Having trimmed the edges straight (thankfully I can still do that) measured the finished piece - a full 2 metres. Having finally sorted out my cm and inches, I went back for another 2m - she might as well have them a bit fuller. They don't have another roll! The lad found another 72" and was going to cut it when I pointed out it was not the same pattern.
I honestly don't know what has happened to my head, I used to be very clear on both cms and inches. Either it is the effect of lockdown, or I have heatstroke after the last few days.