Can't find text in pdf when running Reader DC as RemoteApp

Hi,

We've upgraded our Microsoft terminal servers to also provide applications directly to users via RemoteApp.  We've noticed that with Adobe Reader DC (Continuous release version 2018.011.20040) a pdf is only searchable once, after which any attempts to find text (Ctrl-F or Edit > Find) in the pdf result in "no matches were found."  Has anyone else experienced this issue, or have any ideas what could cause this? 

Thanks