Looks really weird. He was at 19000 ft, then descended in this rather erratic ground track down to 2000 ft, then climbed back to 8000 ft and continued to destination.
Loss of cabin press? He started squawking 7700 about half way during the weird turns.
Or TCU/Icing avoidance ? Limoges’ METARs are full of interesting stuff, and TCUs are much more common and dangerous than a pressurisation loss at FL190. The climb he did just before could also be a sign he tried to outclimb some build ups. For a pressurisation problem you don’t need to go to 2000 feet nor make turns, either.
METAR LFBL 181530Z AUTO 34008KT 310V020 9999 FEW046/// SCT054///
BKN066/// ///CB 07/03 Q1023 TEMPO 29015G25KT 4000
SHRA BKN010TCU=
