Reverse adapter?

Once you have updated the headset adapter it cannot be reversed, have you tried the left buttons on the adapter they are the game/chat balance, you can also try removing the headset lead the adapter then plug back together again.

In order for the 3.5mm headset to work you will need a recent controller with 3.5mm jack. Unless it's an original Xbox One controller from 2013, your controller should have such a 3.5mm jack. Just look at the bottom connector of the Xbox controller. If there
is a 3.5 mm plug next to the USB-like connector on the left, you're good to go. Otherwise you'd need the stereo adaptor or a newer controller.

As for the headset: Make sure it's 3.5mm jack is according to the CTIA specification. There are two major standards for 3.5mm headset jacks: OMTP and CTIA. Both standards have the microphone and ground connection reversed. So if you have an OMTP compliant
headset, the microphone will not work without getting a CTIA to OMTP adapter. You can get those adapters online or in cellphone shops. This adapter simply reverses two wires, so they should be dirt cheap. If a shop wants more than the price of a coffee to
go you're being ripped off for that adapter.

There are 2 standards for 3.5 mm headphone jacks, called OMTP and CTIA. On both standards, the microphone and ground connectors are reversed. So if you use an OMTP compliant headset on the Xbox, the microphone is "talking" to the ground connector of the
controller, while the console is "listening" for the microphone on a silent ground pin.

Please try the following: Open up the messaging tab on your console, and compose a message, but instead of typing text, press the Microphone icon, and try to record a message.

If you are able to pre-listen to your message before sending it, you being unable to talk in a party is a network issue.

If the console doesn't record your voice message at all, and all you hear is silence, then your 3.5 mm headset is probably incompatible.

You can try to buy a CTIA to OMTP adapter (or vice versa, as these adapters just reverse both connectors, they work both ways). That adapter can be found online or in any cellphone stores. Since the only purpose is to reverse two connectors, these cables
are dirt cheap, and if a store wants more than the price of a coffee-to-go for that cable, you're being ripped off.

Be aware that there are two standards for 3.5mm headset connectors. CTIA and OMTP. The Xbox requires the CTIA standard. If your headset is an OMTP headset, the connectors for ground and microphone are reversed and will not work ok the Xbox.

If your headset is OMTP, get an adapter cable for CTIA to OMTP and vice versa.

What headset are you using?

Be aware that there are two standards of headset plugs called CTIA and OMTP. On both standards, the Microphone and ground connector on that plug are reversed.

For a headset to work properly, the headset connector has to be a CTIA standard plug. If your headset is a phone headset (e.g. Apple or some older Android or Nokia compatible headsets), then they use the OMTP standard, and won't work properly.

If you do have an OMTP compatible headset, simply buy a CTIA to OMTP adapter (or since the adapter simply crosses two wires, it is automatically an OMTP to CTIA adapter as well). Also, since the adapter only crosses two wires, these adapters should be dirt
cheap. If a store asks you to pay for this adapter more than you'd pay for a Coffee to Go, you're being ripped off.