With which AP model(s) are you having this problem?
From the Release Notes:
When configured for this version, MR12, MR16, MR18, MR24, MR26, MR32, MR34, MR62, MR66, and MR72 will run MR 26.8.3.
If it is one of these versions, then I would assume thats the issue. You have configured 30.5 but these older APs will run an older version which is "not the ocnfigured version"