Sometimes some users Deauth from Firewall

Hello, sometimes some users deauth from my Firewall box and they lost Internet access because they aren´t authenticate any more so they match implicit deny policy. I should like know why my users sometimes deauth automaticly from my Firewall box if they is on FSSO Agent yet. please follow my screenshot about my issue and follow my currently user settings

config user setting set auth-type http https ftp telnet set auth-cert "*.xxxx.com.br-2022" set auth-ca-cert "FW-FGT" set auth-secure-http disable set auth-http-basic disable set auth-ssl-allow-renegotiation disable set auth-src-mac disable set auth-on-demand always set auth-timeout 1440 set auth-timeout-type idle-timeout set auth-portal-timeout 3 set radius-ses-timeout-act hard-timeout set auth-blackout-time 0 set auth-invalid-max 8 set auth-lockout-threshold 3 set auth-lockout-duration 0 set per-policy-disclaimer disable set auth-ssl-min-proto-version default end

any tip is welcome