We certainly have… 
(Our synology software fails to sync any file from windows that has a fully qualified path, ie including c:\...all subdirectories...\filename.ext that is longer than 260 characters…)
To at least help you figure out if you have files that are in this “danger zone”, I’ve made a stupidly small but maybe useful notebook for checking for danger files:
Future notebooks may include the option to automatically rename them so that they are shorter…but this is a start a least.