My bad (was too excited when i posted that 'fixed' post) , as in I inspect my other projects and other xib files this is still an ongoing issues.The 11.5 update only resolve some of the issues on simple .xibeg: this resolves my tablecell .xibhttps://imgur.com/a/Yg2gpMm

This is now solved on my end by updating to XCode Version 11.5 (11E608c)EDIT: This only resolve some of my .xib especially the simple / non complex one.My .xib files that are way much complex are not fixed at all.

it took me about 3-4 days for my post above which containing the image links to be approved. It was just stayed there with the status was being moderated.I hope that this is can be fixed soon since the connected IBOutlet's name also can't be searched in the Interface Builder which is kinda devastating for a project that is still heavily using .xib.

Well I tried the same thing with renaming using refactor functionality in xcode but it still not showing the renamed IBOutlet's name, the connectivity between .Xib and .swift file does not seem having any issues.Here's the interesting thing that I found just now:I tried using Storyboard and Xib in the same new clean projectIt seems like the interface builder in storyboard is showing the expected behaviour of showing the IBOutlet name .https://imgur.com/lf8M6UEBut when I tried to do the same thing with Xib in the same project it shown that my IBOutlet name is not shown on the interface builder, and just showing it's generic type.https://imgur.com/wUvLXWA