Thanks a lot for your quick response.
The Merge with -PgeographicError=NaN works great. However, it adds the band from the .hdr file as “Band_1”, meaning that if i want to merge several times some new products, the Merge function erases the previous “Band_1”. I can’t find a “rename” module or something to avoid the issue.
From the BandMaths, it works great too but it creates a new BEAM-DIMAP file, instead of adding it to the previous one.
One solution is to convert and rename the hdr to BEAM-DIMAP using the BandMaths module and then use the Merge module. Not elegant but works