Metamask requests not responding on mobile

I have a webapp using web3/ matamask and calling the following:

 await window.ethereum.request({ method: 'eth_requestAccounts' })

and

 await window.ethereum.request({
   method: 'wallet_switchEthereumChain',
   params: [{ chainId: chainId }], 
 });

All working well on desktop but nothing happening on mobile even though I do have metamask installed.

Are we supposed to do something special to communicate with metamask on mobile?