It looks to me that the speakers that are requested not matching the speaker setup reported by your amp. The channels SL and SR are not listed by your amplifier.
2024-04-30 11:57:42.244 T:901 info <general>: Device 4
2024-04-30 11:57:42.244 T:901 info <general>: m_deviceName : hdmi:CARD=vc4hdmi,DEV=0
2024-04-30 11:57:42.244 T:901 info <general>: m_displayName : vc4-hdmi (vc4hdmi)
2024-04-30 11:57:42.244 T:901 info <general>: m_displayNameExtra: SNY SONY AVAMP on HDMI
2024-04-30 11:57:42.244 T:901 info <general>: m_deviceType : AE_DEVTYPE_HDMI
2024-04-30 11:57:42.244 T:901 info <general>: m_channels : FL, FR, LFE, FC, BL, BR, BC, BLOC, BROC
2024-04-30 11:57:42.244 T:901 info <general>: m_sampleRates : 32000,44100,48000,88200,96000,176400,192000
2024-04-30 11:57:42.244 T:901 info <general>: m_dataFormats : AE_FMT_RAW,AE_FMT_S24NE3,AE_FMT_S24NE4,AE_FMT_S32NE,AE_FMT_S16NE,AE_FMT_S16LE,AE_FMT_S16BE,AE_FMT_U8,AE_FMT_RAW
2024-04-30 11:57:42.244 T:901 info <general>: m_streamTypes : STREAM_TYPE_AC3,STREAM_TYPE_DTSHD,STREAM_TYPE_DTSHD_MA,STREAM_TYPE_DTSHD_CORE,STREAM_TYPE_DTS_1024,STREAM_TYPE_DTS_2048,STREAM_TYPE_DTS_512,STREAM_TYPE_EAC3,STREAM_TYPE_TRUEHDz
Requested by the play process:
2024-04-30 11:58:26.562 T:902 debug <general>: CAESinkALSA::GetChannelLayout - Requested Layout: FL, FR, FC, LFE, BL, BR, SL, SR
2024-04-30 11:58:26.562 T:902 debug <general>: CAESinkALSA::GetChannelLayout - Got Layout: FL, FR, LFE, FC, BL, BR, BC, UNKNOWN1 (ALSA: FL FR LFE FC RL RR RC NA)
I have seen in the manual of the amplifier, that it supports different speaker schemes. How many and which type of speakers do you have? Maybe you should ensure to set it to 3/4.1 and try it again.
Edit: Some minutes ago I have looked into my kodi.log. With my receiver I get also BLOC and BROC instead of SL/SR reported. I will test it tomorrow with that files if I come to the same result like you: