No not the same drive and not the same databases, the drive for each database is always internal for each desktop (3x 2TB Disk model: INTEL SSDPEKNW020T8 and in one case Samsung SSD 970 EVO Plus 2TB). The problem happens on all of them so must be reletad or to operating system and file system or sqlite3. I suspect sqlite3 since it is quite consistent (backup is fine and only internal operations are corrupting the database - it can be indexing of the database which creates the problems - however I cannot see how the initial problem created by indexing can get worse by running SELECT SQLs)