Thank you! This is what I see in the logs (Volumes/AutoImport is the folder I'm watching, it's an SMB network share). It seems the folder is nor accessible, but when access it manually (through Finder or Terminal) it reappears without any errors.
2019-12-27 10:02:07.494 HazelHelper[772] DEBUG: Thread 0x600002eb9100: Timer fired for folder: /Volumes/AutoImport
2019-12-27 10:02:07.494 HazelHelper[772] DEBUG: Thread 0x600002eb9100: Run worker for folder: /Volumes/AutoImport
2019-12-27 10:02:07.583 hazelworker[21141] Running worker (v4.4.3) for folder with identifier: 889192459-2.
2019-12-27 10:02:07.585 hazelworker[21141] ###main load address: 0x104642000
2019-12-27 10:02:07.585 hazelworker[21141] ###Noodle load address: 0x104763000
2019-12-27 10:02:07.585 hazelworker[21141] ###CK load address: 0x10472b000
...
2019-12-27 10:02:07.695 hazelworker[21141] Scan folder is not accessible. Exiting.
2019-12-27 10:02:07.699 HazelHelper[772] DEBUG: Thread 0x600002eb9100: Task removed: [21141]
2019-12-27 10:02:07.699 HazelHelper[772] Worker process for folder /Volumes/AutoImport did not check in.