Traffic is '...dropped by fwpslglue_chain Reason: PSL Drop: UP_LIMIT;'

[Louis_Poulin]

Symptoms

• Kernel debug (fw ctl debug -m fw + drop) shows: 
  
  fw_log_drop: Packet proto= ... dropped by fwpslglue_chain Reason: PSL Drop: UP_LIMIT;
• Users trying to browse the web get timeout error messages in their web browser.

Setup is running R80.10 in a HA cluster (per state VS) and one Virtual System.

What does "PSL" means?

What does "UP_LIMIT" means?