Thanks, my network problem is almost gone!
Everything works smoothly, so I installed also XCompose, Zim, Rclone, rclone-browser, bluefish, fruler, gucharmap, graphicsmagick, dooble, ungoogled-chromium and libreoffice. Only Zim (wiki notebook) limps: it starts successfully, but can not not open any note file. Fortunately, with a detailed report asking to submit it because “Looks like you found a bug”.
Many thanks devs for your hard and smart work!