SANDISK IXPAND 16 gb not detected by IPAD

I am using SANDISK IXPAND  for a longtime.Earlier had a mini ipad and working was ok.However bought a new ipad with 11.4.1 update.THIS IS NOT CONNECTING THE SANDISK.Itried uninstalling and re installing no joy.downloaded firmware update 4.5.1 applied.though it says successful still no connectionyour advice is solicited. thanks