Oh that's lucky, no bridge mode on my B535-232 although its not a big deal as its mostly a backup for my VDSL and I do sometimes connect to its WiFi to test access my local VPN from outside the LAN.
Mine has been working well in NAT mode and would probably port forward fine if it wasn’t for the VPN requirement. I know Three is able to give a proper external IP but EE was far quicker here.
Unfortunately my FTTC was terrible. 26/2 with random daily drops. It took Openreach 8 months to bother to track it down, with multiple ISP getting me to jump through multiple hoops and spend a fair sum on replacement routers, cables, filters etc efc. Once they did find the fault (degraded cable up pole outside) they refused to fix it as apparently not bad enough. So I finally ditched them and went 4G only, averaging 50/30 with zero drops.