How to reproduce:

# Open the “EnumFlagDrawerBug.zip” project
# Open the “SampleScene“
# Select The “Bug Demo“ GameObject
# Change the flag of the “Test 02“ property in the Inspector window
# Observe the “Bug Demo” script Component in the Inspector window

Expected results: The flag of the “Test 02“ drawer is shown correctly and is independent of the “Test 01“ drawer
Actual results: The flag of the “Test 02“ drawer is shown incorrectly and is dependent on the “Test 01“ drawer

Reproducible in: 2022.3.14f1, 2022.3.15f1, 2023.2.0a23, 2023.2.0b18, 2023.2.4f1, 2023.3.0a12
Not reproducible in: 2022.3.13f1, 2023.2.0a22, 2023.2.0b17, 2023.3.0a11
Could not test in: 2021.3.33f1 (No properties are shown because of “compile errors“)
Fixed in: 2023.2.0b1, 2023.3.0a2, 2023.3.0a18

Reproduced on: Windows 11 Pro
Not reproduced on: No other environment tested

Note: If some value is selected and the Mouse cursor is drawn outside the drawer box, the check mark will return to the “Nothing“ value