There is a new pull request by Linux-BSD against master on the void-packages repository

https://github.com/Linux-BSD/void-packages firejail
https://github.com/void-linux/void-packages/pull/18370

firejail: update to 0.9.62
Firejail 0.9.60 does not work with some modern AppImages (e.g. NextCloud), but 0.9.62 which was released about 20 dyas ago does.

A patch file from https://github.com/void-linux/void-packages/pull/18370.patch is attached