DLM isn't my 'thang', there are far more knowledgeable folk on here who will give you an in-depth insight as to how DLM and Rambo work together to stabilise the circuit.
What I can tell you for certain is, not every engineer will perform a 'Recalculation' (Reset) as it's officially termed. This could be down to various reasons like ........... not knowing how to, being unawares it can be done, forgetting to do one at the end of the job. So it doesn't always follow that a re-calc will have definitely been done.
Secondly, when we do perform a re-calc, it always puts the circuit back to an open profile ................. ie: 128kbps-40M, 128Kbps-80M ............. depending on the downstream product chosen. If you have historically managed the full 80Meg, I would have expected that the initial synch speed after a re-calc would have jumped back to somewhere around that speed ?? But, it may not stay there dependant on cross-talk levels and/or still a potential network fault ??
Looking at your stats, I would probably guess that a re-calc has not been done if they were taken immediately after the engineer left site ??