You have misread and/or misunderstood my comment about payment and you misrepresent what happened in your question based upon that. Nowhere is scope of work mentioned.
The person in question isn't soliciting for paid work, they are responding to the OPs statement that they are willing to pay for a resolution. Even if that were not the case I can't see a problem with taking tech support off site.
Something that many people forget is that Server Fault is Q&A not tech support. This OP needs and wants tech support as their underlying problem cannot be resolved on site by Q&A.
Here's how it came about
I answered the headline question It is clear from all the comments though that the OP doesn't want to hear that the kernel is acting correctly, as they have 'lots of free memory'. So I left this comment 1
... If you're not going to listen to what people who are clearly knowledgeable have to say then perhaps you should pay for your support because advice is worth what you pay for it. The advice won't be different but you'll have paid for it so will value it more.
and the OP responded
I would happily pay for advice. Do you know any places where I can do so?
So I contacted someone who I'm fairy sure will be able to figure this out and encouraged them to contact the OP.
This won't be straightforward. It won't be solvable by asking the OP questions in the comments. It will require access to the system and time, to resolve.
Q&A is not tech support. Tech support is not Q&A.
1 Note that my comment doesn't say, as the OP above suggests, `that the scope of work was such that they should pay'.