Workspace Explorer shows ⓝ icon for instances

Describe the issue you are having

Workspace Explorer shows (n) icon for instances

Did you connect to an already running interpreter or start the interpreter from RIDE?

Start an interpreter

How do you reproduce the issue?

i←⎕NEW⎕FIX':class c' ':endclass'
Open Workspace Explorer and expand #
it says ⓝ next to i instead of ⓘ

Paste the contents of Help → About (Shift+F1)

IDE:
Version: unknown
Platform: Win32
Date: unknown
Git commit: unknown
Preferences:{
"dbg":"1",
"kbdLocale":"en_US",
"lbarOrder":"← +-×÷*⍟⌹○!? |⌈⌊⊥⊤⊣⊢ =≠≤<>≥≡≢ ∨∧⍲⍱ ↑↓⊂⊃⊆⌷⍋⍒ ⍳⍸∊⍷∪∩~ /\⌿⍀ ,⍪⍴⌽⊖⍉ ¨⍨⍣.∘⍤@ ⍞⎕⍠⌸⌺⌶⍎⍕ ⋄⍝→⍵⍺∇& ¯⍬",
"otherExe":"C:\Program Files\Dyalog\Dyalog APL-64 17.0 Unicode\dyalog.exe",
"selectedExe":"C:\Program Files\Dyalog\Dyalog APL-64 17.0 Unicode\dyalog.exe",
"squiggleTips":"1",
"title":"{WSID} {VER}",
"wse":"1",
"zoom":"4"
}

Interpreter:
Version: 17.0.31153
Platform: Windows-64
Edition: Unicode/64
Date: Oct 16 2017 at 10:27:50

Reproduce the issue by starting an interpreter with the provided expression, then open Workspace Explorer and expand #. Inspect the Workspace Explorer handling for instance icons; done means the instance is shown with ⓘ rather than ⓝ.