urBackup server hang on file backup (Flushing file client)

Running inside gdb (without debug build). Got this error :

2024-12-15 22:24:14: HT: Copying file: "/mnt/NasSshfs/apps/241215-2211/joplin_1/Assets/WebsiteAssets/images/flags/maritime/n.png" (id=5562)
2024-12-15 22:24:14: HT: Renaming file to "/mnt/NasSshfs/apps/241215-2211/joplin_1/Assets/WebsiteAssets/images/flags/maritime/n.png" with hash output
2024-12-15 22:24:14: GT: Linked file "isBinding.js.map"
2024-12-15 22:24:14: Loading file "isBinding.js.map" (metadata only)
2024-12-15 22:24:14: Flushing FileClient...

Thread 46 "fbackup load0" received signal SIGBUS, Bus error.
[Switching to Thread 0xf22f81c0 (LWP 10572)]
0x0060fa7c in ?? ()
(gdb)