Thomas has clarified some weeks ago that the Shanghai Special occurs after the end of Season 2 and the start of Season 3.
That is why we see Marinette still following Adrien and knowing his schedule, since at the end of season 2 she still didn't decide to let him go and take a chance with Luka
See Also
'Miraculous: Tales of Ladybug and Cat Noir' Leaving Netflix in February 2023Netflix Is About to Lose Miraculous: Tales of Ladybug and Cat Noirhow old are Adrien and marinette? | FandomMiraculous: Tales of Ladybug and Cat Noir"NY is chronologically placed between S3 and S4. Shanghai does not have such a precise chronological place. It takes place somewhere between S2 and S3."
So, the cronological order of the whole series would be:
Season 1
Season 2
Shangai Special
Season 3
New York Special
Season 4
