Strange behaviour with Blofeld arps and Digitakt

Any advice with using Blofeld arps and Digitakt?

Having odd issues when changing to patterns containing the arps.
e.g. they dont start immediately and the arp note patterns change.

I make sure the tempos of the blofeld preset and the Digitakt tempo match, also pattern lengths.
Are there any settings on both Digitakt and Blofeld that need to be coordinated?

Any general advice?