Fortigate

hi we have this problem. after updating the firmware from the rel. 7.0.1 (where everything worked perfectly) at rel. 7.0.2 (where the problems started) passing then to 7.0.3 and finally to rel. 7.0.4, all users who connected via proxy policy do not receive the login on their browsers (tried more than one) and if they receive it after reboot of the firewall they connect to the internet for a short time and then can no longer connect . furthermore, all users who connect to the internet via firewall policy have many disconnections. also the problem I am having on two firewalls Fgt 101 and Fgt 201E. Thanks to everyone who can help me solve the problem.