Full freeze spike on spellcasts on enemy heroes.

[Beanie McBean]

Game freezes for 0.5-1.5 sec and console shows

[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur
[Client] server acknowledged to slot 9 client only predicted into 6 slots, full repredict will occur

Happens every 15 sec or so, but the freeze is only notable when casting spells on enemy heroes.
Does it have to do with too many players overflooding the servers due to new patch?