Without more specifics it would be difficult to know what has happened with the fixlet application. Did the action fail? What line failed and with what exit code etc.
How are the machines created? if they are created from ISOs or cloned from VMs missing updates, then they would need to have patches deployed that may not otherwise be needed typically and need “catch ups”.
There is a specific patch involved with this, so it is good to update your base for VMs so that it has it so you are less likely to hit this limit, but if the VMs are getting added to bigfix automatically when created, then you might need to deploy these specific patches long term to prevent issues with RDP.