Status and Tracking: Lock Function overide due to status change?

Hello experts,

Does anybody know whether it is standard functionality that a user with only R_STS_PT authorisation can unlock his/her planning by changing the status to "in process"?

Should it not be the case that I higher hierarchy node or someone with R_STS_SUP authorisation must first unlock the plannig before for somone with only R_STS_PT authorasation can perform any status change? I am currently unsure whether what we are observing is a feature or a bug which we had previously not noticed.

Thanks in advance,

Will