[PROBLEM] Library loads very slowly on iPad using Safari

[suzywong]

Systems:
1. Allo USBSig/DigiOneSig, Moode 7.6.1. Wired Ethernet
2. Rpi3B+, Moode 7.6.1. Wired Ethernet
3. Rpi3B, Moode 7.6.1. wireless.
4. RPi ZeroW, Moode 7.6.1. Wired Ethernet

All are static IP on our home LAN (Netgear 3700 router.) Music stored on Synology NAS(s)

Access via iPad (iOS now 15.3).
Safari exhibits behaviour as described - when scrolling, normally about half a second to load the next tranche of names, occasionally up to two seconds
Chrome only tested on the Allo System (1.). Does not exhibit the issue.

Access via Windoze 10 PC
Chrome does not exhibit the issue. Not tested MS Edge.