Anybody else experience Rumba 'latency', 'slowness' 'missing character' after upgrading to OS V7R2

We had recently upgraded to iSeries OS V7R2 , and about the same time it was reported by our end users (Rumba version 9.4) that they were experiencing 'latency', 'slowness' 'missing character'( when typing quickly on the keyboard a character would not show up in the monitor .  typing on keyboard "ABCD" ... but only "ABD" display . this slowness is exhibited before pressing the <ENTER> key.  

Has anybody else seen an issue like this?

Thanks

Jon