I found an issue when reading Landsat 5 Level 2 data from Collection 2.
The picture below shows the band wavelength on the left how they are set by SNAP now and on the right how they should be.
There is probably an issue with Landsat 4 and Landsat 7 data too. I haven’t checked this.
The data is read automatically by the LandsatGeotiffColl2L2Reader. It seems this reader needs to differentiate between the different sensors.