I got the same problem with hi reject, up from 3 to 20%, I lowered my intensity from 20 to 18 and that solved the problem for me.
I'm also connected to amsterdam:
Hash Rate: 4.68 MH/s
Shares Last Hour: 251
Reject: 2
Reject %: 0.80
Scan and expire on 1 and queue 5, works just fine
