@free4 Sorry for late reply was busy with one Project. Since I added given below code to Login and Error page no error reported so far ( almost 5 days now )
Its a labor camp having any different mobile brands like Oppo , Redmi, Apple, Samsung, HUAWEI, Honor. you just name it. I have two sites in production on 2.5-Dev since one year two only services, Load balancing & Captive Portal ( Voucher )
<input name="redirurl" type="hidden" value="$PORTAL_REDIRURL$">
<input name="zone" type="hidden" value="$PORTAL_ZONE$">
current issue on both sites I am having is related to PHP-FPM repeatedly given errors appearing in syslogs
Dec 22 22:56:14 kernel pid 72021 (php-fpm), jid 0, uid 0: exited on signal 11 (core dumped)
Dec 22 22:38:44 kernel pid 58075 (php-fpm), jid 0, uid 0: exited on signal 11 (core dumped)
Dec 22 22:38:07 kernel pid 15969 (php-fpm), jid 0, uid 0: exited on signal 11 (core dumped)