Maybe it’s ok then. What is your TTE? That’s the estimated time you can hold mFTP. When my TTE is < 40 min I usually know the mFTP is slightly high.
Lots of resources out there to help understand the wko5 model, but this hits the main points as good as any - https://help.trainingpeaks.com/hc/en-us/articles/360031772312-Why-Did-my-Power-Duration-Curve-or-Power-Duration-Metrics-Change-In-WKO5-