Did you get the indication of an FTP rise at the end of an activity via Zwift’s automatic detection? According to an article in Zwift Insider about how Zwift does this: “Your FTP value is calculated at the end of your ride as 95% of your highest 20-minute average power.”
If you put in a particularly stellar performance during a race, that estimation by Zwift is a possibility, even if it seems huge. If you’ve been putting in the work and actually feel much stronger at the moment, that’s great.
If you aren’t comfortable with that value, it’s worth running through the calibration protocol for your Elite trainer – as @Mike_Rowe1 alluded to – and then taking the same FTP test that you’ve done previously (when you’re well rested, as I’m sure you know already) to put your mind at ease. You can always manually modify your FTP value in Zwift and Zwift Power, if you desire.
Let’s not forget that, in the end, our FTP numbers are abstract values. Different test methods (Zwift estimation versus Zwift FTP ramp test versus a full hour FTP test) will inevitably return different numbers because they measure performance differently, even on the same equipment. If you can exclude the likelihood of the equipment that you’re using having lost accuracy, use the test of your choice to consistently track the changes in your abilities. Ride on!