Impossible to set 'tick' parameter / vertical grid of x-axis in plot window below a certain value

I am running a transient a simulation from 0 to 500us. The x-axis of the plot window by default comes with tick marks / vertical grid lines every 100us. Right clicking on the x-axis, I can set the tick to any value higher than 50us, but not lower (values lower than 50us are not accepted and 100us is automatically used instead). Is it an expected behavior?

Yes, axis setting in Qspice waveform viewer is not that free.
My guess is that, x-axis maximum number of ticks is about 10 and y-axis is about 11, that why minimum tick value is restricted.
0 to 500us with tick=50us gives x-axis 11 ticks (0, 50us, 100us, … 500us), which is not allowed and therefore, tick=50us is not accepted.
For example, if you run simulation only up to 499us, you can set tick=50us as it only display 10 ticks.
[I may be wrong, just a guess with some tests]

You can use simulation from 0 to 500us with tick=50.1us.

By update to Build Dec 9 2023, tick=50us is accepted with 0 to 500us range.
12/09/2023 Corrected a roundoff error regarding adjusting/limiting plot tick size.

With more test, this is my observation
Depends on waveform viewer windows size, there are two possibly maximum number of ticks in x- or y-axis, which are 6 or 11. Minimum allowable tick size is range/10, and effective tick size may reduce to range/5 if change of windows size.