In the course of less than 12 hours zellij grew from 93 MB to 1227 MB in roughly 2 kB increments per minute. Closing the tab running btop will release the stolen memory.
I will append a comment to the Microsoft GitHub issue mentioned above a little later.
Thanks! If you could also specify how you measured it and attach some debug logs (there are instructions in the issue template) that would be great. Because my instance has run overnight without issue and I'd love to be able to reproduce this.
I will append a comment to the Microsoft GitHub issue mentioned above a little later.