Node won't respond to Corner Tool

[Sethster]

Hey guys. So CS6 finally took a crap on me when I updated my Mac's OS last week. Decided to finally make the switch to Affinity and so far I'm really liking what I'm seeing. I've run into a slight problem though with the corner tool and I could use some help. 

• Running on Mac OS 10.14.6
• Running Affinity Designer 1.7.3
• I opened an existing .ai file with a line that had a stroke. 
• I expanded the stroke to make a shape
• All the nodes on the shape were represented by the usual square except for the top node which was represented by a small circle.       

                     

• I can use the Node tool (white arrow) to move all the square nodes around like normal, including the top circle node. 
• When I go to use the Corner Tool though, it works on all the square nodes, but not on the circle node. 

Here's a link to a short screen cap video showing the issue, if that helps: https://www.loom.com/share/bd431ab4d03742cabe4c5c68a5edd3a3

I feel like I'm missing something simple here, but I just don't know what. Any help would be appreciated. 

[Old Bruce]

Using the node tool select the round node and convert it to a square one

 It is the farthest left.

[Sethster]

37 minutes ago, Old Bruce said:

Using the node tool select the round node and convert it to a square one

 It is the farthest left.

Old Bruce! You are magic sir! Thanks a million!