I can also confirm the reg entry key worked for me. It does raise the question where multiple machines are used with multiple accounts across different companies and perhaps different desktop files and documents there is lots of scope for multiple copies of files and mess, so caution is necessary in this scenario. For keeping consistent desktop and docs on one account it is ideal assuming it works automatically at some point, but again this could cause some problems for some users.
Interestingly on my main work laptop the reg entry was already present , this is the machine that has always worked. On my other laptop changing the reg entry enabled the function. Question is why did it work on one and not the other with the same account. Client version the same on both 18.135.0705.0003 (targeted release channel)