Something similar happened to me. Matek F405, Slim+ and F.Port. During the flight the controller changed his mind about the receiver protocol and said it was DMS (Spektrum). RC channels went crazy. Changed flight modes, maximum aileron and elevator deflections. Death spiral in full swing. Fortunately 100m altitude, empty field. Four seconds later and at a speed of 30 m/s it was all over.
First and last flight with F.Port. Back to SBUS after rebuild. Stable release 4.0.9 not so stable.
A word of warning when using F.Port.