Yes, same thing has happened to recordings set on my Beyonwiz T3.
It has been noticed and several users on the Beyonwiz forums have noted this as well.
Same symptoms as you have seen, series set to record, but particular episodes that match the recording criteria (not repeat etc) are not being flagged to record.
Updating the series recording results in the series recording being removed entirely.
Re-setting the series recording for those shows results in the timers being created correctly.
For example, I had "Good Game", "Good Game SP" and "Good Game Pocket" set as series recordings.
"Good Game" was unaffected.
"Good Game SP" had a greyed out series recording icon next to its next valid instance on Saturday.
"Good Game Pocket" had greyed out series recording icons for all valid episodes this week.
Selecting "Update series on Beyonwiz T3" and selecting the default values resulted in the series recording being deleted.
Re-creating the series recordings queued the episodes up properly.
I have not delved into any more series recordings to see which other ones may be broken.