In RM8 v8.1.8 on Mac Catalina, and a copy in a Win10 machine restored from the RM8 Mac backup, I have a bit of a note that looks to be plain text.
No different colours, no indication there’s any option to do anything with it if I hover over it in RM8.
But in the App (IOS 14.8.1 on an iPad Mini) it shows up as coloured blue and if I click on it on the app I get asked if I want to send message or add to contacts, so I presume my iPad thinks it is an email.
I cannot recall now whether I would have pasted as plain text from the source but should have if I didn’t (I do so wish that was still an option to set overall as it is in RM7).
In the actual source used it is a link to order a certificate.
Further down the note is a FamilySearch link
or at least so the App tells me.
I cannot see the link from within RM8 as the note wont soft wrap (reported) , and if I select the screen view of the note it is off to the right, with no means to scroll.
So to view or edit, I’d need to use an external editor - so why have an apparent editor within RM8??? Rhetorical question, no need to answer that bit 
If I widen the screen it shows as a blank space
If I hover over where the link actually is, in plain text according to the App, my RM8 cursor changes to the little hand for a link (which cursor isn’t captured in the screen shot given I had to move it to take the screenshot)
Any takers for explanations?
I will be submitting this to Support, but haven’t yet, given I’m still hoping a future version will have improved editing
Update: Thinking about the blank link, my working assumptiion for that is that because it was a bit of text starting with http://… that the editor might be trying to be too helpful converting it to the html for a link but NOT giving it a name of the link itself, hence the blank??