Ok cool.
I mostly use static machines. I only realy use flex machines when resampling.
Anyway. Octatrack is in essence 8 tape recorders. Those recordings are stored in RAM, which is limited and volatile. That means, unless you save the recording to the disk, recordings can be destroyed by either recording over them via user error, or it is destroyed when you turn the machine off.
So to resample your midi sequences from the same source, remember to either switch track recorders, or save your samples to disk.
Example. Track recorder 1 records you main sequence. Track recorder 2 records your counter melody. Both 1 and 2 record from the same source, lets say A, your mono synth.
A flex machine is not a recorder. It is a machine for playing samples in RAM, or samples on the track recorders. RAM is limited.
A track recorder is a recorder, its job is to sample.
A static machines job is to stream samples from the disk. Disk space is huge…
Do not expect to understand octatrack only 7 hours in. It will take time. Enjoy the ride. Dont rush it.