Channeling would indicate a possible change by you unless of course it was there before and you just didnt previously notice.
The new grinder is different.
Dont think because its the same make and model that its identical.
Sunbeam have had quality issues lately; hence them sending out a lot of washers to adjust the grind.
My old EM0450 didnt need any and neither did anyone elses bought around the same time.
I think an indication of how bad that problem is, is the fact that they sent me some washers when sending me something else, even though there was no discussion of any grind adjustment problem.
It reads to me like your new grinder is not set fine enough.
Try grinding a bit finer.
The other option, if you have room in the basket, is to add a bit more coffee.
Both of those things will slow down the pour.
DONT do both at once in the first instance.
Only change one thing at a time.