I have done a lot of stress testing with a 3-folder configuration including nested folders, etc., and I must say that I am simply unable to reproduce the issue. Syncthing has so far managed to always sync all the changes with no issues. I also want to say that I am running with Max Conflicts set to 0.
Anyhow, I have now run stindex on the databases from two devices. This is not the same situation, as the one described in the first post, as now the “Out of Sync Items” are actually listed, but the devices are still stuck in “Syncing”, so there is that.
This is how to the situation looks like. I am attaching screenshots of the GUI and stindex output for one of the out-of-sync files.
Device A
[device] F:4 D:1 N:"folder1/021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"folder1/021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:238356, Permissions:0644, ModTime:2020-10-09 19:58:27.4205179 +0900 KST, Version:{[{D4DZUGP 1602241107}]}, Length:0, Deleted:true, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[], BlocksHash:}
[device] F:4 D:1 N:"folder2/021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"folder2/021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:238286, Permissions:0644, ModTime:2020-10-09 19:22:58.4205179 +0900 KST, Version:{[{D4DZUGP 1602239437}]}, Length:311, Deleted:false, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[Block{0/311/669670638/5ef8052e22ad2b64bd967f73d562c1019bc5688f1c4836702644238320dc7e64}], BlocksHash:e5b434b0f76d0c1f06f5de2f4534c790c8804b1a1b44eb5c9262d8f9fa96ebcf}
[device] F:4 D:3 N:"folder1/021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"folder1/021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:236952, Permissions:0644, ModTime:2020-10-09 19:58:27.4205179 +0900 KST, Version:{[{D4DZUGP 1602241107}]}, Length:0, Deleted:true, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[], BlocksHash:}
[device] F:4 D:3 N:"folder2/021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"folder2/021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:236878, Permissions:0644, ModTime:2020-10-09 19:22:58.4205179 +0900 KST, Version:{[{D4DZUGP 1602239437}]}, Length:311, Deleted:false, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[Block{0/311/669670638/5ef8052e22ad2b64bd967f73d562c1019bc5688f1c4836702644238320dc7e64}], BlocksHash:e5b434b0f76d0c1f06f5de2f4534c790c8804b1a1b44eb5c9262d8f9fa96ebcf}
[device] F:12 D:1 N:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:149984, Permissions:0644, ModTime:2020-10-09 19:57:31.4205179 +0900 KST, Version:{[{D4DZUGP 1602241051}]}, Length:0, Deleted:true, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[], BlocksHash:}
Device B
[device] F:1 D:4 N:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:149984, Permissions:0644, ModTime:2020-10-09 19:57:31.4205179 +0900 KST, Version:{[{D4DZUGP 1602241051}]}, Length:0, Deleted:true, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[], BlocksHash:}
[device] F:1 D:5 N:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:File{Name:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics", Sequence:198, Permissions:0644, ModTime:2020-10-09 19:58:36.4205179 +0900 KST, Version:{[{7LDIBZ4 1602241116}]}, Length:0, Deleted:true, Invalid:false, LocalFlags:0x0, NoPermissions:true, BlockSize:131072, Blocks:[], BlocksHash:}
[global] F:1 N:"021a4c1d-45ae-4228-8137-56940eda6cf5.ics" V:{{{[{7LDIBZ4 1602241116}]}, {7LDIBZ4}, {}}, {{[{D4DZUGP 1602241051}]}, {D4DZUGP}, {}}}
Is there anything useful in the stindex output?