Input-selector works ok with 2 videotestsrc but fails with 2 rtspsrc

Newcomers
1

Hello.
This pipeline works like a charm when switching sink pads in the input-selector. But the next one fails. What I’m doing wrong?
Using 1.20.3 on Ubuntu 22.04.

COMMAND_ALWAYS_ON_VALVE: str = ( "videotestsrc is-live=true pattern=ball " " ! clockoverlay halignment=left valignment=bottom shaded-background=true " " ! video/x-raw,width=160,height=120,framerate=2/1 " " ! videoconvert ! x264enc ! rtph264pay ! queue " " ! selector.sink_1 " "videotestsrc is-live=true pattern=snow " " ! clockoverlay halignment=left valignment=bottom shaded-background=true " " ! video/x-raw,width=160,height=120,framerate=2/1 " " ! videoconvert ! x264enc ! rtph264pay ! queue " " ! selector.sink_2 " "input-selector name=selector " f"! queue ! whipsink whip-endpoint={WHIP_URL} auth-token={AUTH_TOKEN} " )

But this one fails:

    COMMAND_ALWAYS_ON_SELECTOR: str = (
        f"rtspsrc location={SOURCE2} "
        " ! rtph264depay "
        " ! rtph264pay config-interval=-1 "
        " ! application/x-rtp,media=video,encoding-name=H264 ! queue  ! selector.sink_0 "
        f"rtspsrc location={SOURCE} "
        " ! rtph264depay "
        " ! rtph264pay config-interval=-1 "
        " ! application/x-rtp,media=video,encoding-name=H264 ! queue  ! selector.sink_1 "
        "input-selector name=selector  "
        f"! queue ! whipsink whip-endpoint={WHIP_URL} auth-token={AUTH_TOKEN} "
    )