How You Can't Report Bugs Answered
There doesn't seem to be a contact route to report bugs on the Instructables website.
Having encountered a very annoying bug, I searched the Instructables website and found in the Forums "How to Submit Bug Reports" at <https://www.instructables.com/community/How-to-Submit-Bug-Reports/>.
That post has a link to take you to where you can report your bugs. That link is <https://www.instructables.com/community?categoryGroup=help&category=bugs>.
Surprise! That link takes you to .....(drum roll!)....
Which is exactly where you started from.
After about six circuits of this merry-go-round without finding a way to actually get wherever bugs are supposed to be reported, I just decided to post this so everyone else can have as much fun as I did. If they want to.
I think it's a bug, but since I can't find a way to report it, I'll go home now.