How do I mount a Synology remote folder on Android 8.0? My phone is not rooted.

I have shared folders on a Synology drive which I can mount on a couple of different Macs running different versions of Mac OSX. I am assuming the folders are published using CIFS/SMB but I cannot mount them on my Android phone using file manager type applications. So far I have tried "ES File Explorer", "Network Browser" and "File Commander" none of which are able to connect.

I can connect to the Synology home page using a browser on the phone so network connectivity is OK. Do I need to disable/enable firewall/sharing settings on the phone?
No specific configuration beyond the availability of published shares is required.

Sometimes issues arise due to the stability and capabilities or lack thereof of Android apps to mount the shares. The following apps have been tested and were able to reliably and successfully access SMB shares from the Synology server (at 2 June 2020) using a simple combination of (server) IP Address, username and password:

LAN drive, Cx File Explorer, X-plore, File Commander