I have one user Office365 Pro on Windows 10 English but he has loaded Japanese language as default.
In OUTLOOK application on his computer he was able to search emails from users in local Address book until last few weeks but now we are noticing funny character where "From:" used to be. as highlighted in picture. 
If the user selects first item which is just a name then he is able to find the emails from the searched user but if he selects the yellow highlighted contact which is from the address book then the search shows emails from other users but not the user in search.
This was working until March for sure and maybe middle of April so it could be a Windows or Office update issues.
