Otona ni Narenai Bokura wa - Ch. 21 - Pool weather

[Moshu_Reads]

This will probably break the time loop

probably not, because the hourglass was broken on the panel.
The only way, I think they can break the time loop, might happen when they are unable to forget/ do not want to forget about each other because a part of the reason why they are stuck in this loop is because they had forgotten about their past ( in a vague sense)