[mythtv-users] "Tuner 5 has an error"

[mythtv at kosowsky.org]

I am using mythtv 29.1 under Ubuntu 18.04 running under kernel 5.0.9.

I initially installed a Hauppauge WinTV-quadHD PC Express card that
provides 4 dvb inputs:
	 /dev/dvb/adapter0/frontend0
 	 /dev/dvb/adapter1/frontend0
 	 /dev/dvb/adapter2/frontend0
 	 /dev/dvb/adapter3/frontend0

The Frontend ID for all is: LGDT3306A VSB/QAM Frontend.

I then added a Hauppauge WinTV-HVR-955Q (aka Hauppauge Digital TV
Tuner for Xbox One) USB tuner.

That tuner is recognized by Linux as /dev/dvb/adapter4/frontend4.
It works fine with VLC.

Mythtv recognis the card appropriately as /dev/dvb/adapter4/frontend4
with Frontend ID also LGDT3306A VSB/QAM Frontend.

Everything seems fine, but I can't switch to the card input on LiveTV.
System info says "Tuner 5 has an error" with details:
       Tuner 4 [DVB: /dev/dvb/adapter4/frontend0] has an error
(Note numbering is off because I name them Tuner 0 through 4 whereas
System info seems to count them 1 to 5,

The mythtv-setup configuration for the tuner is the exact same as the
other 4.

When I cycle through the tuners on Live TV, I go from Tuner 0 to 1 to
2 to 3 and back to 0.
(Note that when I type M->Source, I get only the first 3 tuners...)

The syslog shows for each tuner switch (but no errors for the 'skipped' Tuner 4):
Apr 24 23:49:03 consult kernel: [83954.235912] dvb_frontend: dvb_frontend_get_frequency_limits: frequency interval: tuner: 42000000...870000000, frontend: 54000000...858000000
Apr 24 23:49:03 consult kernel: [83959.284003] dvb_frontend: dvb_frontend_get_frequency_limits: frequency interval: tuner: 42000000...870000000, frontend: 54000000...858000000

Any hints on how to track down the 'error' for the last tuner.