Analyse variable font with two axis

Dear Georg,
I have a little problem:
After I input four TrueType fonts in Glyphs, I got a variable font with two axis. But when I analysed the variable font, I got four new TrueType fonts. And one of them is different from the initial input TrueType font. Why are they different?
Please see the attachment for the detail.

Thanks and have a nice day!

I don’t see an attachment. Can you send it by email (to support at this domain)?

I’m sorry I forgot to send you attachments yesterday. I have sent the attachments by email. Please check, thank you!