I do not know why this error occurs, it does not work neither with matomo.php nor with matomo.js, decode the content of the URL and do not detect the reason for a bad request, I leave below the line where the error occurs. as well as the content of one of the parameters of the beacon the other one
dK = g.sendBeacon(dD, dC)
error: Failed to load resource the server responded with a status of 400 ()
dD <-- ********/matomo/matomo.php?action_name=********ing.com&idsite=3&rec=1&r=396625&h=18&m=0&s=14&url=https%3A*%2F*%2F********ing.com%2Fstatic_en%2F&_id=f024ebfaa9d4a137&_idn=0&send_image=0&_refts=0&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=3840x2160&pv_id=4VDQ3p&pf_net=327&pf_srv=100&pf_tfr=2&pf_dm1=498&uadata=%7B%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Google%20Chrome%22%2C%22version%22%3A%22119.0.6045.159%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22119.0.6045.159%22%7D%2C%7B%22brand%22%3A%22Not%3FA_Brand%22%2C%22version%22%3A%2224.0.0.0%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platform%22%3A%22Windows%22%2C%22platformVersion%22%3A%2210.0.0%22%7D
dC <-- Blob {size: 678, type: 'application/x-www-form-urlencoded; charset=utf-8'}
Note: I obfuscate the url because it does not allow me to publish.