Regarding disabling SSL VPN tunnel mode

Hi Ramadan

That's true and that applies to all FG models.

https://docs.fortinet.com/document/fortigate/7.6.3/fortios-release-notes/173430/ssl-vpn-tunnel-mode-replaced-with-ipsec-vpn

If you can't move to IPsec then you may move to ZTNA.

https://docs.fortinet.com/document/fortigate/7.6.3/administration-guide/317228/zero-trust-network-access

No, it won’t. You use a loopback interface for the SSL VPN and create a policy and a VIP for it. That way, you won’t need to disable it from the settings, you can just disable the policy instead.

What's 7.6.3's document @AEK referred to is saying is you need to use IPsec VPN over TCP like on port 443, just like SSL VPN.
One possible issue is I heard a rumor that IPsec over TCP feature would be dropped with FortiClient VPN (free version without EMS). If that's true you have to have a licensed FortiClient EMS (or the cloud version of EMS) with full version of FortiClient. I'm assuming you can afford that. I'm keenly realizing that's not an option for individual small FGT user though.

Toshi

You're right, starting from version 7.6.3, Fortinet plans to phase out SSL VPN tunnel mode. This applies across platforms, including your 1801F. If you're in a region where IPsec VPN is restricted, consider checking whether Fortinet will still support SSL VPN in web mode or offer any exceptions. It's best to confirm with Fortinet directly for region-specific policies and alternative secure access options.