I was recently looking into the Indian Journal of History of Science because in 2021 they handed the journal production over to Springer.   So articles are now paywalled on the Springer site.  BUT all articles are also freely downloadable from the IJHS website at INSA in Delhi.  I wrote and asked INSA what was going on, and they said that they had struck a formal deal with Springer for this arrangement.  So it's legit.  But you would never find this out from the Springer website.

Best,
Dominik