I’m trying to create a backup of important files from my Windows PC to a Raspberry Pi running Linux using Syncthing. Some files fail to sync without any error message or other information. They simply remain listed under “Out of Sync Items”. The files that fail to sync are those with non-ASCII characters in their filepath. When changing any one of these characters to an ASCII character, they are synced without a hitch.
When trying to solve the problem I found an old Support topic: Symbols & Non-English Alphabets in Filenames, however in that topic it was made clear that “every character in your files’ names must be a single unicode symbol, letter, or number”, the main problem in this topic was that some characters is actually two characters with the example of the character ‘Å’ sometimes being “Latin letter “A” and combining ring above “°””. After reading this, I checked the characters that where failing with unicodeplus.com however they seemed to be of the single character form. However, just to be sure, I pasted the correct single-character form into the file name to no avail. Besides, when copying the character shown in the file name inside the ‘Out of Sync Items’ in my RaspberryPi and pasting it into the aforementioned website, it successfully identifies that it is only one character. And since it doesn’t really matter what the file is actually called, if the receiving end says it is a valid single unicode character, then it shouldn’t run into a problem with it. I’m using v2.1.1, Windows (64-bit Intel/AMD) on my PC and v2.1.0, Linux (64-bit ARM Container) on the Raspberry Pi.

