I face the same issue as described previously by John Wiegley. After several hours (sometimes even less than an hour), emacs freezes completely without the option to recover it.
A backtrace also leads to lisp_align_free:
#0 0x000000000055aa0e in lisp_align_free ()
#1 0x000000000055acd9 in sweep_floats ()
#2 0x00000000005603ac in garbage_collect ()
#3 0x00000000005607e7 in Fgarbage_collect ()
...
This is especially cumbersome since I am running EXWM and have to therefore recover my session in a tty by restarting my desktop manager.
I will add a timer to run the garbage collector every few (5) seconds so I can hopefully track which event changes the state in a way that leads it to the observed freezing behavior.
I report back back if I find out anything new. In the meanwhile, I am happy for any suggestions on how to debug this issue.