In the display it is difficult to distinguish whether the sorting mode for the list of package functions is switched on or off.
The image shows the unsorted list on the left and sorting on the right. The difference is hardly noticeable.
[Linked Image]
Maybe that can be changed.

I see a yellow underlining. Can you go to Help > Support Info and send me the text of the Info tab page. Can you also let me know your "Reduce icon sizes" setting (Preferences > User Interface)?

Attached is the content of the info page. The behavior hasn't changed with beta 4. However, I'm a bit confused about the reference to the yellow underline. It will surely come because of the chosen theme (Midnight Express Yellow).
The difference in the appearance of the sorting icon (sorted/unsorted) is actually interesting for me. I have to take a closer look... See picture where the red arrow is pointing.




PL/SQL Developer
Version 15.0.0.2043 Beta (64 bit)
Theme: Midnight Express / Office2019Black
Windows 10 Build 19043
de-DE(1031)/Deutsch (Deutschland)

Physical memory : 4.193.780 kB (906.412 available)
Paging file : 6.094.324 kB (1.324.136 available)
Virtual memory : 137.438.953.344 kB (137.434.076.636 available)

Parameters
E:\prg\db\tools\plsd15\plsqldev.exe

Preferences
Session mode: Dual
OCI Library: <none>
Use OCI7: False
Allow Multiple Connections: False

Preference Files
E:\prg\db\tools\plsd15\Preferences\Default\Default.ini
C:\Users\frankg\AppData\Roaming\PLSQL Developer 15\Preferences\frankg\default_dark.ini

Debug file
E:\prg\db\tools\plsd15\PlSqlDev.elf

Plug-Ins
*Active Query Builder (E:\prg\db\tools\plsd15\PlugIns\ActiveQueryBuilder.dll)
*PL/SQL Documentation (plsqldoc) (E:\prg\db\tools\plsd15\PlugIns\plsqldoc.dll)
(* is Active)

Aliases
adbfg1_high
adbfg1_low
adbfg1_medium
adbfg1_tp
adbfg1_tpurgent
...

Homes
OraClient19Home1 (E:\oracle\product\19.0.0\dbhome_1)

DLLs
E:\oracle\product\19.0.0\dbhome_1\bin\oci.dll

TNS File
E:\Oracle\product\19.0.0\dbhome_1\network\admin\tnsnames.ora

Using
Home: OraClient19Home1
DLL: E:\oracle\product\19.0.0\dbhome_1\bin\oci.dll
OCI: version 12.1 (19.3.0.0.0)


Character Sets
Character size: 4 byte(s)
CharSetID: 873
NCharSetID: 2000
Unicode Support: True
NLS_LANG: GERMAN_GERMANY.WE8MSWIN1252

Process
Working Set = 160.509.952
Memory = 77.797.364
GDI Objects = 916
User Objects = 3092
Handles = 637

Monitor
PixelsPerInch = 168

Id = 0
PPI = 168
Primary = True
Handle = 65537
Left = 0
Top = 0
Width = 2876
Height = 2037

MainFormOnTaskbar = True

Thanks. We'll investigate.

Do other "pressed" buttons have the same problem? For example the "Lock" button in the SQL Window? It should have a yellow underlining like this:

Note that the underlining only applies to the "Midnight Express" styles.