this is the first time I heard -mě- pronounced like "mje" and not "mňe"
Mě is mostly pronounced as mně, but in some regionns it can be mje. But here i can hear mně.
Yeah, you're right. It's subtle
Is there somethng as old square
yes, it is
Can I have this link, too? Why -sky?
Check here https://forum.duolingo.com/comment/25346240?comment_id=36339702
However, the old voice might have pronounced it indeed wrong. Please check the current female voice.