The behavior of suspend-then-hibernate has changed as of v252.
HibernateDelaySec no longer specifies the time a system will sleep and then go into hibernation. The new behavior is that the system will sleep until there is 5% battery left and then go into hibernation.
If the current battery capacity is higher than 5%, the system suspends for interval calculated
using battery discharge rate per hour or HibernateDelaySec= if former is not available.
I wondered why my laptop wasn’t hibernating all week and came across this issue this morning. It looks like there is a new option being added to achieve the previous behavior.
Yes, it works again in v253, thankfully. I believe that as long as you have HibernateDelaySec configured in sleep.conf as well as suspend-then-hibernate in logind.conf it will work. On my system (manjaro-gnome) I had to extend the delay in gnome settings to be longer than the IdleActionSec parameter in logind.conf.