First machine, singer 2282 second hand (inactive for 3 years), top thread visible on back no matter the top tension. Already checked: correctly threaded (thread goes through tension disks), bobbin tension is
SINGER Tradition 2282 Sewing Machine for sale online | eBay
SINGER Tradition 2282 Электромеханическая швейная машина
Singer Tradition 2282 Sewing machine | Back Market