with--drive-chunk-size 1G --drive-v2-download-min-size 200M and 12 files in upload, every files is 9GB, i upload only large files.
The issue is when finish some files and there are only a few files to complete, in this case, is slow 
My ping from every server isn't less than 25ms, my ftth anyway is in island, so maybe the cable under the sea, have more hop. But is strange that are two weeks that also via browser i have this issue.
Last mouth, via browser worked like a charm, now... not i'm very unlucky