No problems have developed. The slowing of the rate at which the foundation is accepting the grout is indicative
that cracks near the hole are mostly filled and that the grout has to be pushed further to reach cracks which
are still more or less open.
The sketch shows the possible penetration of grout so far:
So the hole is taking the grout at a reasonable rate, and all is going well. There is no need to change anything and on we go for the next 15 minutes.