The Pet Palette displays only commands that are valid for the clicked node.
Try the other, inside node of that Wall corner, which is probably the end of the Wall's Reference Line. The Stretch commands appear only when you click the end node of the Reference Line, since Walls are stretched by either end of their Reference Line.
When you have one Wall the Reference Line of the Wall extends all the way to its side. However, when there is an L-joint, the Reference Line of the two Walls may join at a different point. Find it and you will find your lost Pet Palette commands.
Loving Archicad since 1995 - Find Archicad Tips at x.com/laszlonagy
AMD Ryzen9 5900X CPU, 64 GB RAM 3600 MHz, Nvidia GTX 1060 6GB, 500 GB NVMe SSD
2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac27
