That doesn’t explain “Christians” continuing the practice for 35 years. Need some consistency please.
Sure it does. Most of the original Christians were converted Jews.
If you read the book of Acts, you can see that there was controversy in the early church as to whether converted Gentiles should be taught to practice Judaic law after their conversion. The decision was that they did not, but that did not change the fact that at least some converted Jews continued to observe many of the things they had throughout their lives.
Messianic Jews today continue to observe many of those same things, but they do so with the knowledge that they point to Jesus, their Messiah.