Andor should be all before Rebels because Maarva's brick marks her death date as 7972.216.4 which is the CRC calendar before the BBY/ABY one is utilized. A New Hope is 7977, so the 7972 date lines up. The ".216.4" after it should signify how long into the year according to the subreddit r/StarWarsReference. Going off how they've calculated other released dates from the Scum and Villainy reference book, Maarva passed late March or around March 20th. Going back in the season from there, Andor starts in January which still covers the 5 BBY date at the beginning of the show.
So Andor is the beginning of 5 BBY and Rebels starts at the end of 5 BBY since the Empire Day episode has to land in the middle of the following year according to some past Pablo Hidalgo tweets. The Kessel incident they mention would then be referring to Solo years prior instead of the Rebels premiere, and works a little better since I'm sure news of a Jedi on Kessel would've came up in those Coruscant scenes.