FLStudio with ' Rescan already verified plugins ' selected. This is because the the WAVES SHELL plugin is unchanged and so FLStudio does not know something is new there and won't rescan it to discover your new or updated ...
FL combines them after a full scan and defaults to VST3 when actually favorited and then used. Here's a screenshot:
[img:3owts03b]https://i.imgur.com/NICQA5n.png[/img:3owts03b]
Combine VST and VST3 versions of a plugin ...