Before verifying the engine, I also cleared the launcher cache along the path: C:\Users%username%\AppData\Local\EpicGamesLauncher\Saved\webcache_4430
And one more thing, when I verified the engine, its files were slightly modified, so the launcher had to download about 400 MB, maybe this also affected it. Alternatively, you can delete a couple of files from the engine folder so that the launcher has to download something for the engine.
I’m not sure, but maybe this will help you.