I cant confirm the actual bonus procedure from Stake, I'm just saying based on what I know but I doubt a user will get a bonus if he do not play at all for too long time. My own case was I did not play for weeks (2-3) and I still get weekly bonus but the amount was about $5 if I remember it correctly.
That means some how your wagger from previous still can count on the bonus reload.
Try again for more than 1 month without playing, login, or wagering anything and let's see did you still can get some reload bonus again or not. As from article, I read from stake the distribution some bonus will be always secret.
So maybe they could be distributed the bonus not in the end of the month, that was really lucky for everyone who wagering in the past 7 weeks or maybe the whole month still not passed.