On screen layout malfunction with <Caps> key and XRDP sessions

You can't turn on upper case letters with <Caps> key. Only turn off works correct with <Caps> key. With <Shift> key anything works well.

• SSH session => works correct
• RDP sessions with Windows => works correct
• RDP session with XRDP => faild

1. Login (with english language settings)
2. Open RDP session with XRDP client
3. Test#1: Type in any text with keybord. Result: lower case letters
4. Open context setting with <ctrl> + <alt> + <shift>
5. Select input method "on screen keybord"
6. Test#2 "on screen keybord": Type in any lower case letters with mouse. Result: lower case letters
7. Select key <Caps> with mouse onto "on screen keybord"
8. Test#3 "on screen keybord": Type in any text with upper case letters onto "on screen keybord" (with mouse) Result: lower case letters!
9. Turn off <Caps> key with "on screen keybord"
10. Test#4 "on screen keybord": Type in any text with lower case letters onto "on screen keybord" (with mouse) Result: upper case letters!

Test#1: OK
Test#2: OK
Test#3: <Caps> Turn on faild (lower case letters into remote session, but it must be upper case)
Test#4: <Caps> Turn off works, but result is false (upper case letters into remote session, but it must be lower)