Chrome webrtc-internals showing audioLevel as 0 and there is no audio - webrtc

Question

I am using Kurento for audio-only Webrtc. We have two browser apps from where users can connect and listen. But for one of the app, there is no audio in Chrome. And in other browsers it is working fine. Also, the other app works perfectly fine in Chrome. For the app, for which there is no audio, I checked chrome://webrtc-internals/, I found audioLevel, totalAudioEnergy and [Audio_Level_in_RMS as 0. Which seems like the issue. But I am not able to find the reason why it is 0 as same stream is being audible with non-zero audio attributes.
SDP Offer generated from chrome:
v=0
o=- 5216768741743449485 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE 0
a=msid-semantic: WMS
m=audio 9 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 110 112 113 126
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:RqhJ
a=ice-pwd:nzZ+GB+RAJ6H80ToE7uxpaZk
a=ice-options:trickle
a=fingerprint:sha-256 49:17:98:CC:EE:53:46:B4:A0:86:3B:29:B8:E4:E5:E8:E1:CD:49:B0:B5:AA:D8:3A:68:EF:2D:96:31:FF:F9:AE
a=setup:actpass
a=mid:0
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:3 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:5 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
a=extmap:6 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
a=recvonly
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=rtcp-fb:111 transport-cc
a=fmtp:111 minptime=10;useinbandfec=1
a=rtpmap:103 ISAC/16000
a=rtpmap:104 ISAC/32000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:106 CN/32000
a=rtpmap:105 CN/16000
a=rtpmap:13 CN/8000
a=rtpmap:110 telephone-event/48000
a=rtpmap:112 telephone-event/32000
a=rtpmap:113 telephone-event/16000
a=rtpmap:126 telephone-event/8000
SDP Answer from Kurento:
v=0
o=- 3788596538 3788596538 IN IP4 0.0.0.0
s=Kurento Media Server
c=IN IP4 0.0.0.0
t=0 0
a=msid-semantic: WMS
a=group:BUNDLE 0
m=audio 1 UDP/TLS/RTP/SAVPF 111 0
a=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=sendonly
a=mid:0
a=rtcp:9 IN IP4 0.0.0.0
a=rtpmap:111 opus/48000/2
a=rtpmap:0 PCMU/8000
a=setup:active
a=rtcp-mux
a=fmtp:111 minptime=10;useinbandfec=1
a=ssrc:4159551798 cname:user3791831093#host-88916abf
a=ice-ufrag:dfqB
a=ice-pwd:nvfOteYfAIimzPMmD1E1Gx
a=fingerprint:sha-256 E5:D2:D9:1E:82:DD:21:E4:1B:8F:FC:62:F6:2C:FF:5B:C3:C4:17:75:97:DB:F0:BC:B5:F2:2C:6A:EB:35:83:4E
Any thoughts/suggestions/debug steps? Please share. Thanks in advance.