The format of the file name is written in Section 3.6 of ApostilleWhitePaper.
First of all,
[Filename] - Apostille
There is one minus (-) to get there.
next,
[Transaction hash] – Date
There are two minuses (–) entering between.
According to my test, both a minus (-) one or two succeed in audit.
If you create Apostille with the current NanoWallet, there are two minus (–) in both.
Although it is not a problem in fact, it is a situation that it is not created with the file name as specified, so I think that it is better to unify if possible.