On Discord there are People (including me) (probably there are more) who have a lot of thick strining with firmware 2.2.0.
The string-test-towers left and right are printed after each other, with the same filament and settings, only diiference is the firmware.
On the left FW 2.2.0
On the right FW 2.1.9
I have also filmed the retraction of both, but i cannot upload the movies here.
In FW 2.1.9 the retraction goes smooth with time between the retraction and the feeding (the arm is travelling from point to point) .
In FW 2.2.0 the retraction is fast and it direct feeds again (no waiting between retraction and feeding) especcialy the feeding is very fast, so I (and others) think this is (part) of the cause of stringing in 2.2.0
Movies of the retraction are here:
FW 2.2.0: https://discord.com/channels/697655770681966697/714411949399736321/773318240855654400
FW 2.1.9: https://discord.com/channels/697655770681966697/714411949399736321/773318288734158858