Menus not being shown after switching off TV during playback

[Don Pedro]

Hello! I have the following problem:

Software
XBian version: 20180509-0
XBMC/Kodi version: 17.6
Overclock settings: None

Hardware
Device type and model (e.g. Raspberry Pi Model A/B 256/512 MB, CuBox-i i4Pro, ...): Raspberry Pi 3
Power supply rating: N.A.
SD card size and make/type: 16GB
Network (Ethernet or wireless): Ethernet
Connected devices (TV, USB, network storage, ...): LG TV with active and working CEC

Log files
Link to logfile(s): -

Problem description:
If I switch off the TV during a playback the menus of Kodi will no longer be shown. Kodi is still active in the background, the TV is playing sounds on key presses and I can change the live TV channels, pause playback with space, etc.

How to reproduce:
- Play some live TV
- Switch the TV off without stopping the playback
- Switch the TV back on, the video is still playing
- Press x (or back or ESC) to show the home screen, the menu does not come up any more!

Some remarks:
- When pressing back or ESC it appears Kodi is not responding at all. Nevertheless it does react, it just doesn't show the menu. When you use x instead the playback will be stopped as expected and you end up with a completely blank screen. The TV's info button shows you that this is not "no picture" but a blank, all black picture (in e.g. 1080p @ 60Hz or something else).
- This effect does not(!) depend on what reaction I choose for the CEC adapter when switching the TV off. I can even set it to "ignore" but the effect stays.
- Also C (or other keys) don't show a context menu or something any more.
- The Raspi is still reachable via SSH and when triggeríng a reboot there normal operation recovers after the restart.
- Kodi does not recover if I trigger a HDMI hotplug event (by unplugging and repluggin the HDMI cable).
- The problem does not show up if I stop the playback with x prior to switching off the TV.
- The effect is securely reproducable on my installation.

Anyone has that also and can reproduce? Is that a bug in Kodi? Any workarounds available? I guess disabling CEC might supress the problem, however This is not really a "nice" workaround...

THX

Don