Helium and RAK Support teams are aware of the fact that many OG and RAK/MNTD Hotspots are not issuing challenges and may be out of sync. Here's a summary of what's going on and what's being done about it.
Support teams noticed that many Hotspots were not only struggling to stay in sync, they also had 95% or more of their disks full. This was causing poor disk performance. When a Hotspot restarts, it checks whether or not the disk is too full and if it is, the Hotspot will wipe its disk / reload the chain from a Snapshot. (As mentioned previously, this is the reason why some Hotspots that seem to be working go back to syncing mode.)
If the Snapshot isn't too far behind, this process only takes a few hours, but currently, Validators aren't able to automatically generate them. Core developers are manually blessing snapshots. (There are a few bug fixes in the works to address this.) The most recent Snapshot is about 3100 blocks behind and we're working on being able to manually bless a more recent one.
Last night, the Helium support team decided to force all Hotspots within their control to restart and if they had full disks, they would have cleared and reloaded from Snapshot. We suspect these Hotspots will be syncing for a few hours or up to a day. We did this by issuing a 2022.01.12.2 release (which is identical to 2022.01.12.1). We also informed other Makers that It's not a typical GA and it doesn't require any actions on their part.
There are some improvements ready to be released to help with Snapshot loading and better disk usage/management but we chose not to do a full release on Friday. These changes will go out on Monday. The support teams will continue to monitor the situation over the weekend but we wanted to keep you all informed on what's going on.
Source: Official Helium Community Discord