Running motors under 900ERPM in speed control

Hey guys, 

this is my first post here. Up until now I always was just a quiet reader.

my question is as follows. Currently I run a big outrunner motor (watercooled and hall-sensored) with my MakerX G300 on my Dyno.
However there is the following problem that must be a software issue: whenever I run the motor over the tool under 900ERPM in speed control mode it cuts out aka the VESC goes into braking-mode and stops the motor immediately.

when set to 900ERPM the motor runs fine and when I apply a load there is no issue. Puts on full torque.

however the problem occurs when I set it to 899 and downwards from that.

To clarify: when running in current control and putting a load on the motor forcing it under 900erpm or at startup there is NO ISSUE. 

So there must be a setting that prevents it from going below 900.

there is another thread here from 2019 where somebody said:

„The 900rpm minimum can be changed in the configurator, standard firmware. I have mine at 300 for my hoverboard“
however he didn't specify further.

please help me out here!

thank you!

louis