Hi, just FYI in Safari for MacOS 10.15.4, you can no longer edit goal times for segments.
That’s weird, but OK. Both my macs on 10.15.4 do not show the edit pencil. No big deal, other browsers work.
I just checked on my iMac also (this morning was on my MacBook Pro) but it works there too. But, yeah, if it works on another browser - still weird…
I haven’t used this feature before but I have seen segments on Strava after I ride the same course.
What is the difference between editing the time versus just trying to ride the segment faster when you are up for it?
What has to be setup for it to work?
You need the Segment Hunter IQ app on your Garmin if you want guidance from Xert during your effort. Otherwise, this feature is useless 
Have you tried clearing your Browser’s cache? If you’re still experiencing issues, might be worth sending a note to the support team with as many details as possible.