Reviewing ahead boosted card intervals by around 100% instead of my deck settings' 50%. Any clue why?

I’ve been reviewing ahead with a filtered deck for the next two days since I won’t be having much time, but I noticed that I was getting absurd intervals when I answered correctly. These were all cards with more than two weeks intervals, and my settings on the home deck were set so that the interval would increase by 50%. However, I noticed my intervals were actually being boosted by around 100%.

Similarly, the card lapses barely reduced intervals, instead of using the home deck’s setting of 30%.

This was my first time using ‘review ahead’, and so far these issues never occurred in the home deck. Does anyone have a clue why this might happen?

When you review ahead, it’s like if you were actually reviewing the day the cards you are reviewing were meant to be seen, so lapses are calculated from the future.

That makes sense, but, say, lapsed cards were conserving about 90% of their interval. Wouldn’t this be unusual if my deck’s lapse setting is 50%?