Cursor colour anomaly when changing character with POKE

Problem
In VGA SCREEN 0, the colour of the cursor should equal the attribute of the underlying character. However, if we change the attribute with POKE, the cursor does not change accordingly.

Steps

1. Run program below

What happens
Cursor stays grey (COLOR 7)

What was expected
Cursor becomes red (COLOR 4)

Program
10 DEF SEG=&HB800
15 CLS: PRINT"test"
20 LOCATE 1,1,1,0,8
30 FOR I=1 TO 8052 STEP 2
40 POKE I,4
50 NEXT
100 GOTO 100

Notes

PC-BASIC version: 2.0.4
Operating system version: all