What you are doing in terms of her picking up and dropping the scent etc, is just fine.
In the beginning of the video she is exhibiting really nice searching patterns, and again, you are doing an excellent job of allowing her to work. Notice how at about the 1:00 minute mark she overshot the scent column and then actually steps backwards. That is great- very useful skill in the field when dogs kick the truffle out behind them. At that point she starts to pull away and move on, but as you approach she comes back to it which is good to see. Her lying down when you ask her to “show you” is fantastic!
You are doing a great job of allowing her time to work.
At the tail end of that session (Lesson 3 beginning of week 2) you could see her going in and out of working mode. That is completely normal in complex environments. This where endurance training starts to come in to play- and you build to it. It is quite a large area you have her searching. Keep that up and remember not every session may be flawless. There are many factors, but keep practicing. You really cannot spend too much time at this stage just solidifying these searching behaviors, and building endurance. Practical application in the field, dogs are out “working” for quite some time so you must build to it slowly.
Overall, great job you two!
I would say it is fine to start hiding it under mulch (I have not watched the next video yet) but keep doing area searches like this where it is not buried, but obscured. Once you start burying, you really need to make the search area much smaller and gradually increase it again to encourage sucess. There are always things to work on, like precision, alerts, etc. It is tempting to start burying right away, and I know Lola can do it, but don’t rush this stage as it is critical to long term development. This is a stage in training that we use for endurance training which is critical in practical application.