I upgraded to latest version of https://github.com/solana-labs/wallet-adapter in order to use the Mobile Wallet Adapter in Android devices. AS the time of writing this, the only wallets that have integrated this are Solflare and Phantom.
Everything went smoothly when testing the wallet-adapter-react-ui on a website running locally and exposed through ngrok when using Solflare, but when testing Phantom it just failed without any message, the transaction request never reached phantom wallet, and the app just crashed.