Hello,
I am an interior Design photographer and I just changed from the Mark IV to the R5. There is so much noise and some colorful dots all over my photos.
I downloaded the raw file. Around 200 "bad pixels" due to the long exposure. The ones from your print screen are not removed in LR because they are in clusters. I think one strong pixel in the middle spills over to the other four due to the long exposure but I am far from an expert. You can try the sensor cleaning via menu method and see if that will remove the clusters.
The overall noise level is normal. Your print screen to the right.
