Already losing voices with 4 tracks playing

Hi guys/girls!
Yesterday I had my first jam that kind of led to a song... but with the 4th track, already voices where dropping out.
I had a drum kit track, a sample-synth track, a synth track and another kit track with a time-stretched sample.
The main thing(s) that kept being dropped/cut off where long samples.
I did extensively use some delay automation in the kit track, and all tracks had some form of delay and reverb, but I wouldn't suspect voices being stealed/dropped so quickly... but removing the kit delay automation did seem to help. Also, I got voices dropping when they Deluge needed to load something, like a new synth preset.
It also seemed to help when not using time-stretching. (i.e. minimising processor load seemed to help)
Is this normal behavior?
I've seem demo's on youtube of people doing much wilder stuff, without voices being stealed or dropped.
Comments
suspect=expect
If u're not using the soon-to-be new firmware beta, the new SD streaming feature frees up a lot of juice
Also, easy on the analog delays, use digital for most stuff, and adjust the voice priority setting of tracks, for example.
When is the new beta due to become a release?
I don't know when exactly it'll be, but it's in the final stages of bugsquashing I believe
Hey @dob! Is the new alpha firmware helping with this particular issue at all?