Enable DEV mode as shown below
<!-- DEV MODE switched off by default and can be switched on during development -->
<!-- but has to be switched off for productive use on a Java server! -->
<context-param>
<param-name>com.sap.ui5.resource.DEV_MODE</param-name>
<param-value>true</param-value>
</context-param>
<!-- END: DEV MODE -->
Make sure "Disable Cache" is unchecked in Network tab of chrome.
Hope it works.