Yes, that would be technical difficulties. But imagine someone using this exchange for the first time for an instant swap, but instead of swapping faster, it takes more than 1.5 hours. This means it won't be instant, and due to that bad experience, users might decide to leave that swap permanently. So ultimately b1exch will lose a potential user.
However, I am not arguing against the concept of the instant swaps. Since there is blockchain use, it would take time to confirm on the chain. Users have to accept this delay. But unusual delays are a matter of concern, and b1exch should focus on improving their service. For the technical issues, b1exch should also notify users so they will realize why it was delayed.
People mostly don't actually need instant swaps but it's always more convenient to have something fast, not actually instant but not too slow for resulting in uncomfortable experience. With users, it's not only about the convenience but also about their feeling of losing their funds. If a swap takes 1.5 hours to be completed for receiving the fund, many users will feel fearful, even go panic a little bit, especially if it's their "first time" of experiencing swap or swap on privacy exchanges or it's a swap for their big fund.
Surely technical issues to cause unsmooth services for users, not only "Instant Swap" need to be investigated by the team, fixed for providing better and smoother service in the future.