Finnish Stitch 1+2, M2 (Müsen Stitch)
Müsen Stitch (Germany)
UOO/UUOO M2 (from left to right) (video)
This stitch was introduced on a German website nadelbindung.de the creator of which wrote he/she (I couldn't find a name) invented the name Müsen Stitch based on an article by Gudrun Böttcher, "Nadelbindungstechnik: Mittelalterlicher Textilfund in Müsen".
Otherwise this stitch is similar to Finnish Stitch 1+2 (Mammen Stitch), but the connection stitch is M2 (see the photo above).