There are actually six different TV series:
1959: https://en.wikipedia.org/wiki/Die_Muminfamilie
1969: https://en.wikipedia.org/wiki/Moomin_(1969_TV_series)
1972: https://en.wikipedia.org/wiki/New_Moomin
1977: https://en.wikipedia.org/wiki/The_Moomins_(TV_series)
1990: https://en.wikipedia.org/wiki/Moomin_(1990_TV_series)
2019: https://en.wikipedia.org/wiki/Moominvalley_(TV_series)
I highly recommend the 1990 Polish stop motion TV series https://en.wikipedia.org/wiki/The_Moomins_(TV_series). The only one that, to me, captures the magic of the books.