Symbol Layer Drawing not joining stacked lines correctly
I am using ArcGIS Pro 3.6.0. I've had trouble getting through to IT to update my software lately, but until now it hadn't really been an issue. I'm not even sure it is a versioning issue, but it's seemed to manifest out of nothing so I can't rule it out.
I have frequently made static maps using what I refer to as "stacked lines" (I doubt I came up with that) which refers to a single feature line symbology with 2 stroke layers within it. Very common product for me. Hitherto, all it took was for me to enable Symbol Layer Drawing in the Symbology pane to get the thousands of little line segments that make up the corridors I'm symbolizing to give the appearance of a single line. Without the Symbol Layer Drawing, it looks like a pock-marked, uneven, dashed line. To be expected.
Now the Symbol Layer Drawing isn't behaving like it has and I have no idea why. When I'm zoomed in farther in than is ever worthwhile, it looks correct. But when I zoom out to a useable scale it's as if the Symbol Layer Drawing turns itself off and I'm greeted with the pocky lines.
It's best viewed from the layout pane. Below is what it looks like when I'm "only" zoomed in to 426%:
Here is what it looks like when I'm zoomed in all the way to 666%.
In the map view, it seems the "threshold" is 1:99,999. At that scale or beyond (+ 99,999), the symbol layer drawing turns itself off. I have been looking through all the menus I can think of to try and locate where the setting could be but I have been unsuccessful in finding anything. Hence why I've gone so far as to ask here.
