While uploading two small contentassets with sfdx I get a "storage limit exceeded". But the storage usage looks good

How can this happen? How can I upload my files?

We recently started development with high-volume events on the Streaming API on a partial copy sandbox

After very few events we get after this request
{
clientId=4r31ek1ohkbxa8aw1me5i8j9li28t
, channel=/meta/subscribe
, id=2,
subscription=/event/NotifyMDM__e
, error=403::Organization total events daily limit exceeded
, successful=false
}

this response

com.salesforce.emp.connector.CannotSubscribe: Unable to subscribe to [/event/NotifyMDM__e:-2] [https://11880--uat.my.salesforce.com/cometd/43.0] : 403::Organization total events daily limit exceeded



If we look at MonthlyPlatformEventsUsageEntitlement, we get Max: 750000 and Remaining: 750000.

Why exceeds the usage limit so fast and where can I see a valid usage measurement?

We recently started development with high-volume events on the Streaming API on a partial copy sandbox

After very few events we get after this request
{
clientId=4r31ek1ohkbxa8aw1me5i8j9li28t
, channel=/meta/subscribe
, id=2,
subscription=/event/NotifyMDM__e
, error=403::Organization total events daily limit exceeded
, successful=false
}

this response

com.salesforce.emp.connector.CannotSubscribe: Unable to subscribe to [/event/NotifyMDM__e:-2] [https://11880--uat.my.salesforce.com/cometd/43.0] : 403::Organization total events daily limit exceeded



If we look at MonthlyPlatformEventsUsageEntitlement, we get Max: 750000 and Remaining: 750000.

Why exceeds the usage limit so fast and where can I see a valid usage measurement?