I’ve been using DD WRT firmware on my linksys router to tether my iPhone for internet connection and has been working fine until iOS 14 update. Hotspot still works fine for wireless connection but no longer feeds the router network connectivity. Tried resetting router and reinstalling the firmware and reconfiguring. Everything proceeds as normal but router is not live.
iPhone XS, iOS 14
I have the same problem and went through all the same steps as you to no avail. I live in a rual area and rely on my hotspot for internet. I have it tethered to a Netgear router running DD-wrt. I do this so I can connect more than five clients and have better wifi range. IOS 14 update broke that setup. I wish I never upgraded. I'm pretty sure apple is not going to do anything to address this. There not going to support anything other than PC or MAC usb tether problems I'm sure. Thinking about downgrading back to ios 13 but its a hassle.
Can you share with me the Synology support phone number or email that you used to get the hotpatch?
You need to create a ticket on their support system and ask for the iOS 14 hotpatch:
IPhone Tethering Not Working After iOS 14 Update
