merge Sentinel 5p projected tiff files without the overlapping at borders?

I have used gdalwarp for extracting Sentinel 5p L2__AER_AI data product to 14 tiff files in EPSG:4326 CRS.

These projected tiff files can be gotten from mundi_tiff - Google Drive

Then, I used for merging them: -a_nodata 9.96920999999999943e+36 -o merged.tiff file_1.tiff file_2.tiff ...

The output looks correct, but it has pixel overlapping at the borders (opened on QGIS and applied style with pseudo color palette), and I don’t know what is the best way to flatten these pixels properly.

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