Still seeing this issue unfortunately. Backups are being taken every 6 hours. Last mention of any saving activity in the console was at 06:37 where the server was left in a save-off state. A backup (folders created with world files) was taken at 12:37 & 18:37 but no activity was shown in console. Around 19:00 (after I grabbed the attached logs) I manually typed a save-on which gave me the "Automatic saving is now enabled" message.
[18:36:39] [main/WARN]: Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
[18:36:39] [main/WARN]: Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
[18:36:39] [main/WARN]: Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
[18:36:39] [main/WARN]: Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[18:36:39] [main/INFO]: Reloading ResourceManager: Default, wandering trades v1.4.0.zip, silence mobs v1.1.0.zip, more mob heads v2.8.2.zip, dragon drops v1.3.0.zip, double shulker shells v1.3.0.zip, cauldron concrete v2.0.3.zip, fast leaf decay v2.0.3.zip, invisible-item-frames-v2-5-1.zip
[18:36:41] [Worker-Main-9/INFO]: Loaded 7 recipes
[18:36:41] [Worker-Main-9/INFO]: Loaded 1150 advancements
[18:36:43] [Server thread/INFO]: Starting minecraft server version 1.17.1
[18:36:43] [Server thread/INFO]: Loading properties
[18:36:43] [Server thread/INFO]: Default game type: SURVIVAL
[18:36:43] [Server thread/INFO]: Generating keypair
[18:36:44] [Server thread/INFO]: Starting Minecraft server on *:25565
[18:36:44] [Server thread/INFO]: Using epoll channel type
[18:36:44] [Server thread/INFO]: Preparing level "world"
[18:36:44] [Server thread/INFO]: Preparing start region for dimension minecraft:overworld
[18:36:45] [Worker-Main-6/INFO]: Preparing spawn area: 0%
[18:36:45] [Worker-Main-8/INFO]: Preparing spawn area: 0%
[18:36:45] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:46] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:46] [Worker-Main-10/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-10/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-10/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-8/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-7/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-9/INFO]: Preparing spawn area: 0%
[18:36:51] [Worker-Main-6/INFO]: Preparing spawn area: 3%
[18:36:52] [Worker-Main-9/INFO]: Preparing spawn area: 30%
[18:36:53] [Worker-Main-8/INFO]: Preparing spawn area: 30%
[18:36:53] [Worker-Main-10/INFO]: Preparing spawn area: 55%
[18:36:53] [Server thread/INFO]: Time elapsed: 8785 ms
[18:36:53] [Server thread/INFO]: Done (8.903s)! For help, type "help"
[18:36:56] [Server thread/WARN]: UUID of added entity already exists: bgu['Armor Stand'/40, l='ServerLevel[Nick's World]', x=16562064.50, y=1000.00, z=-22242911.50]
save-off
[00:36:34] [Server thread/INFO]: Automatic saving is now disabled
save-all
[00:36:44] [Server thread/INFO]: Saving the game (this may take a moment!)
[00:36:45] [Server thread/INFO]: Saved the game
save-on
[00:36:55] [Server thread/INFO]: Automatic saving is now enabled
save-off
[06:37:05] [Server thread/INFO]: Automatic saving is now disabled
latest.log
screen.log
supervisord.log