How to get back wired bridge button switch option?

I have a GL-MT300N-V2 and for quite a while there was an option to set it to wired bridge mode by flipping the switch on it. It was a bit finicky and sometimes took several switches back and forth, but it worked. After a somewhat recent update this option was removed. Because of this I’ve found that the travel router often makes using any app that involves streaming over my network, like Plex or Moonlight, a real pain to do. Recently I haven’t been able to get them to work at all.

I’m pretty good at computers in general, but horrible at anything involving networking. Figuring out all the correct port forwarding options with a double NAT situation is a nightmare. And even when all the settings look correct, it often still doesn’t work. Just setting the router to bridged mode was an easy way to solve this, but now I can’t do that anymore. I know there’s ways to do a wired bridge manually, but I wasn’t able to figure it out.

I’ve ended up rambling a bit more than I meant to, but basically I’m wondering if there’s some way I can get this bridged mode switch option back, or at least an easy way to set the router to wired bridge mode manually.

Well, I was able to find a solution on my own. I found some old firmware and flashed it. I don’t like having to use outdated firmware, but I guess there aren’t any other options.