Question about dates prior to 1752 - specifically January1/Tevet 3/Hanukkah 8th day coincidence

Hello, I was interested in the rare occurrences when Hanukkah 8th day falls on Tevet 3 and I found that this always seems to coincides with January 1 (falling on a Sunday, January 1) on the Gregorian calendar. I found that this does occur, but that it seems very rare. The first occurrence of this that I was aware of was in 2017, Prior to that, I only found two other Gregorian dates - 1797 and 1550. I went back as far as Hebcal would allow (the year 2 C.E.) and did not find any more, but then I read that 11 days were added to the Gregorian calendar back in 1572 (which now makes complete sense as far as why no other occurrences happened before that date). However, it does not explain the single occurrence of "Hanukkah 8th day/Tevet 3/January 1" that I found in the Gregorian year 1550. Could this be due to an error in Hebcal algorithm? Or, is there another explanation for this? Please can somebody help with this question....?