When Yarbo is resting under an apple tree, these are values
I think it’s mostly the HDOP there, as anything over 2 is unusable. Quality is also less than 0.5. But you need at least 4 shared satellites with the DC for it to be able to try and figure out its coordinates. With only 6 L2, there doesn’t appear to be enough shared quality satellites for it to go to status 4. I’d try it at a different time of day, maybe even night time. The daytime warming of the atmosphere can generate interference.
Some AI generated info:
For the most reliable RTK performance in areas with tree cover, aim to operate in the early morning (before 12 PM) or overnight, while avoiding early afternoons. These off-peak times experience reduced atmospheric (ionospheric) interference and provide a better configuration of overhead satellites