Without any input on my side and after 2 seasons of happy cooperation, Litchi suddenly quit connecting with my Mavic 2 Pro. The app was purchased and installed via Amazon Store when such was allowed for custom Android OS of CrystalSky. I did that on both CS I owe, and both Litchi installation quit working. Accordingly to Litchi's tech sup there is no other explanation but remotely forced disability of certain app version, for whatever reason. Yes, THEY can do it in the background! Update to newer (4.18.0-a) version solved the issue ...