Sylvain Guintoli was disqualified from the first two free practice sessions at Motegi. The decision was made by the FIM Stewards Panel after the technical inspections carried out on his motorcycle. In fact, the commissioners analyzed the engines used by the French rider and discovered they were prototypes for the 2020 engine.
Point 126.96.36.199 of the regulation provides that wild cards (like Guintoli) must use the engines approved for the current season and there can be no changes made. However, Suzukibvdecided to try new parts, therefore, going against the regulation.
That's why Sylvain was disqualified from the FP1 and FP2 but was able to take part in the FP3 and continue the race weekend once a regulated engine was installed.