Tvheadend

I have a DVB-T network created and DVB-T(2) tunner connected to it. The tuner is CXD2854 DVB-C/C2 DVB-T/T2 ISDB-T.
I have created a new MUX and set the delivery system to DVB-T2. All other options except frequency I set to AUTO. Unfortunately scan fails and founds no services. In logs I have found the following:

2021-05-05 13:40:46.221 mpegts: 602MHz in DVB-T - tuning on CXD2854 DVB-C/C2 DVB-T/T2 ISDB-T #4 : DVB-T #0
2021-05-05 13:40:46.221 subscription: 0950: "scan" subscribing to mux "602MHz", weight: 6, adapter: "CXD2854 DVB-C/C2 DVB-T/T2 ISDB-T #4 : DVB-T #0", network: "DVB-T", service: "Raw PID Subscription" 
2021-05-05 13:40:51.222 mpegts: 602MHz in DVB-T - scan no data, failed
2021-05-05 13:40:51.222 subscription: 0950: "scan" unsubscribing

First I thought there is something wrong with signal, but everything works as expected on TV.
After playing with settings a bit I realized that I seems to be a bug I can reproduce all the time.
Steps to do:

1) Edit MUX and set delivery system to DVB-T and scan status to PEND
2) Let TVH scan the MUX - this will fail, because it is DVB-T2 and we set it to DVB-T
3) Edit MUX and set delivery system to DVB-T2 and scan status to PEND
4) Let TVH scan the MUX - this will work and it will find all services
5) Edit MUX and set scan status to PEND
6) Let TVH scan the MUX - this will fail and I am unable to play any channel

All future scans will fail as well, until you repeat above procedure. This is the only way I have found so far to get services detected but still no way to play any channel. When trying to play channel I got:

2021-05-05 13:51:08.270 subscription: 0952: service instance is bad, reason: No input detected

Although there is EPG available for all channels in that MUX.