Ubuntu 24.04 is spamming several of these entries in syslog:
wpa_supplicant[1736]: wlp3s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-62 noise=9999 txrate=390000
The solution is to raise the wpa_supplicant logging level and restart networking:
mkdir -p /etc/systemd/system/wpa_supplicant.service.d/
vi /etc/systemd/system/wpa_supplicant.service.d/log.conf
# add these lines
[Service]
LogLevelMax=4
# save & quit
systemctl daemon-reload
systemctl restart wpa_supplicant.service
systemctl restart NetworkManager.service