I have a GL-AR750S-EXT Slate and an iPhone 6S with visible service installed in our 5th wheel. I have had this setup for about 3 years, at first I had problems with the internet service, tracked that down to high ping on Visible, disabled mwan3 and this worked flawlessly for 2+ years. Around June I updated to V4.3.25 and again the internet connection was flaky, disabling mwan3 did not help, in fact was unable to remove the mwan3 package because of dependencies I did not understand. We did not use the RV for months due to medical issues and it sat at our storage facility with the monitoring kind of working, very flaky but enough to at least check the temperature. Then the iPhone 6S battery failed so I purchased a reconditioned iPhone SE with 5G. Long story short I was never able to get the new pone to work more than a few minutes when tethered. the wireless both 2G and 5G were also flaky. I could get it to function by tethering an Android tablet to the router and using the wifi hotspot on the phone. I tried changing cables and power supplies all to no avail. a few days ago I reloaded firmware V3.216 disabled mwan3 (again couldn’t remove the package due to dependencies). Now everything works flawlessly system has been up for 4 days without a problem. anyone have any ideas why V4.xx firmware causes these issues?
I own several older GL iNet routers, including an AR750S-EXT that used to be my main travel router. After testing the 4.x firmware on my AR750S and other older GL iNet routers, I found that the routers become slower, less stable, and generally unpleasant to use compared to running GL iNet 3.x or OpenWrt firmware on the same hardware.
To me the reason is simple. These older devices do not have the CPU power or memory to handle what GL iNet is trying to push into 4.x. It feels like the company has shifted its attention to newer hardware with multiple cores and much larger memory, and the older products are now an afterthought. The 4.x builds for them feel like stripped down and poorly tested leftovers. Meanwhile OpenWrt continues to support these routers properly, and the current OpenWrt 24.10.x releases are fast and stable.
Based on the state of 4.x on older hardware, I feel that GL iNet should have kept a small team maintaining security fixes for the 3.x firmware and never offered 4.x onto anything with a single core CPU and 128MB of RAM. Every GL iNet router I own runs either 3.x or OpenWrt because those are the only options that still work well on this class of hardware.
I would recommend staying with 3.216, knowing that it is less secure, or going to OpenWrt 24.10. There is a newer beta version of 4.7.2 for the AR750S, but as it has not been updated in 9 months, it is probably dead firmware now that will never make it to production status.