Yes, most likely. For example,

https://www.amazon.com/Portable-Definition-Projector-Jadpes-Ultra-HD/dp/B0867SCDJF/

"1080p" but "Physical Resolution: 800x480" (this is the resolution of the display chip)

This one's even worse

https://www.amazon.com/Lingery-Projector-Supporting-Compatible-22X8X16CM/dp/B086DBGD81/

"Supporting 1080p", "Display Resolution 320 x 240"