Or their RF gain is turned down.  The S-Meter on most rigs (non SDR rigs) is based on RF gain and is useless for anything but self-reference and is NOT a measure of signal strength at the antenna or anywhere else really.  It's really not even good for self reference.
Mathematically it works like this:
SMeter = S*GainWhere S is the signal level in volts at the antenna and that gets multiplied by the RFGain.  In most every SDR system the SMeter is correct and  measures the antenna signal only (no gain).
So since gain is involved the SMeter scale no longer means 6dB per interval.  It's either greater or less than that so makes the SMeter horribly inaccurate.
This is a well known problem.
Mike W9MDB



On Thursday, September 29, 2022 at 11:47:52 PM CDT, Reino Talarmo <reino.talarmo@...> wrote:

>Anyone who finds that disconnecting their antenna from the receiver results in little or no change in the reading on the WSJT-X 'thermometer' when receiving only band noise is indeed very fortunate - their ambient noise level must be extremely low!

Or their antenna or receiver is not working properly at all, hi!

73, Reino OH3mA