Re: Bubble 476 by A. T. Greenblatt (Asimov’s SF, March-April 2021) sees two characters (who are working in two different “bubble universes”) exchange emails. Geo works as an astronomer on an abandoned space station looking for habitable planets for humanity, and Deni as an admin assistant/writer/video monitor on, presumably, one of the planets that NextEarth has discovered.
After some back and forth between the two characters that gives background and character information as well, as describing their current locales, temporal anomalies start to occur: this becomes apparent when some of the emails they receive are from the future.
While this latter event is unfolding, Geo also notes his station is detecting an increasing number of supernovas and (spoiler) eventually it becomes obvious that all bubble universes are breaking down (violent sandstorms become a feature of Deni’s emails). Both characters experience catastrophic events (although it seems like Geo survives but Deni doesn’t).
This story didn’t really work for me as (a) the bubble universe/temporal problem seems a bit contrived and (b) the story peters out at the end.
* (Mediocre). 5,100 words.