I’ve had a look at the logs and I can see that at 1.55am the MIDI note input commands were processed in 5ms, then after returning at 11am and switching to a different project the note input takes 400-800ms. The logs showed that the slow note input operations caused substantial spacing calculations, which suggests that each edit had a major effect on the spacing, which requires a lot more things to be recalculated.
There are many things that can cause substantial recalculations, especially if you have long bars or items crossing barlines. If you have more than one tab open that also adds to the CPU load. We do find occasional problems where more things are being recalculated than are needed. If you can describe a specific set of steps with a project that reproduces the problem then someone on the team may be able to dig into it.