So I went through this exact same headache last summer when I picked up my Bravia. I thought my old controllers would be fine, but the lag on the X90K built-in Bluetooth is just weirdly inconsistent. Honestly, the most reliable fix I found after hours of testing was just biting the bullet and getting the Sony DualSense Wireless Controller PS5 White. Since the TV and controller share the same ecosystem now, the handshake is a lot more stable than the legacy DS4 protocol. I noticed way fewer dropped inputs during fast-paced stuff. Another trick if you want to keep using your existing pads without the lag is grabbing an 8BitDo Wireless USB Adapter 2 for Switch/Windows/Mac/Android. I plugged this into the USB port on the side of my Sony, and it basically acts as its own receiver, bypassing the TVs internal Bluetooth stack entirely. This is huge because the Android TV Bluetooth priority is often low compared to video processing. When I used the adapter with my pro controllers, the input felt basically native. Just make sure the TV is in Game Mode too, because sometimes the X90K resets that if it doesn't recognize the device properly as a console. It is kinda annoying to setup but once it is done it is solid. If you are really in a pinch for tonight, maybe check if you have a long USB cable lying around, tho playing wired is obviously a vibe killer for the living room.

Building on the earlier suggestion, if you want to dodge that lag without spending a fortune on a brand new DualSense, I have a couple budget-friendly ideas that actually work. Over the years I've realized that Sony's built-in Bluetooth is just super picky and prone to interference. The safest move for reliability is actually to avoid Bluetooth entirely and go with something that uses a dedicated USB dongle. In my experience, the Logitech F710 Wireless Gamepad is a total lifesaver for this. It is usually way cheaper than first-party controllers and uses 2.4GHz wireless which is way more stable than the TV's internal radio. Ngl, it looks a bit like a chunky toy from 2010, but it connects every single time without that annoying input delay. Another solid pick if you want something that feels more modern is the 8BitDo Pro 2 Bluetooth Controller. Its usually twenty bucks cheaper than the official Microsoft ones and the build quality is surprisingly legit for the price. I've tried many cheap knockoffs that turned out to be total junk, so I usually stick to brands that have been around a while for safety. If you're in a rush before your friends arrive, see if a local shop has these in stock. Just plug the receiver into the USB port on the side of your X90K and you should be good to go... definitely beats pulling your hair out over Bluetooth pairing screens all night.

Late to the party but I have some thoughts based on testing about a dozen setups. If you're still fighting lag, it is usually because Sonys internal Bluetooth module gets slammed with interference from the TVs own hardware. Tbh, swapping brands is sometimes smarter than just buying more Sony gear. I have found these two to be the most reliable for Android-based Bravias over the years:

• 8BitDo Ultimate Wireless 2.4G Controller with Charging Dock
• The 2.4G connection is way more stable than any BT pairing I have tried on the X90K.
• <a href=" https://www.bhphotovideo.com/c/search?Ntt= SteelSeries+Stratus%2B+Bluetooth+Gaming+Controller+for+Android+and+Windows&BI=8941&KBID=10361&SID=12345&DFF=d50" target="_blank" rel="nofollow sponsored">SteelSeries Stratus+ Bluetooth Gaming Controller for Android and Windows
• It is optimized for the Android backend and handles the handshake much better than the older DS4 units. Quick tip: if you go the USB dongle route, use a small USB extension cable to move the receiver away from the back of the set. The metal in the panel acts like a shield and basically kills the range if it's tucked directly into the port.

Ugh, I totally feel your pain with that input lag. I had high hopes for the built-in Bluetooth on the X90K too, but it turned out to be a massive letdown with older gear. It is basically unplayable for anything fast-paced, which is just not as good as expected for a TV this pricey, ngl. Honestly, skip the headache and just pick up a Sony DualSense Wireless Controller PS5. Sony definitely prioritized their own newer hardware for the pairing protocols... it just works better. If you prefer the offset sticks, the Microsoft Xbox Wireless Controller Bluetooth 2020 Model is actually surprisingly stable on Google TV too. Quick tip tho... make sure you turn off the A/V Sync setting in the TV audio menu. It sounds totally unrelated but it actually clears up a huge chunk of that wireless latency. Good luck with the friends tonight, hope you get it sorted.

Ok adding this to my list of things to try. Thanks for the tip!