No analysis since yesterday

Hi there

I’m using matomo since many years without any problems.
Since two days there are no analysis.

On the Developer Tool in Firefox is an issue:

POST https://www.xyz.xy/piwik/matomo.php?action_name=www.xyz.xy | Home&idsite=3&rec=1&r=430866&h=19&m=35&s=18&url=https:/www.xyz.xy/index.htm&urlref=https://www.xyz.xy/History.htm&_id=123456789&_idn=0&_refts=0&send_image=0&cookie=1&res=2560x1440&pv_id=4Hc5fI&pf_srv=32&pf_tfr=0

Status 400 Bad Request
Version HTTP/2
Referrer Policy no-referrer-when-downgrade

I think it’s the same problem like here:

What could it be?
Can you help me?

Kind regards,

Benno

…strangely enough, everything has been working again since last night!