Common mistake when training with resistance bands is not taking into account the variable resistance curve and therefore failing to set up the exercise with a suitable level of resistance for adequate stimulus.
Using a banded seated row as an example this could be sitting too close to the band anchor point making the exercise not tasking enough. Alternatively you could be sitting too far back and the level of resistance is too much for you to complete a full rep.
Even if you sit somewhere in-between this the level of muscle activation can still be improved with a slight body rock as shown in this video. This allows you to extend the small section of the resistance curve that provides an ideal level of resistance for you, therefore allowing you to get the both worlds, adequate tension throughout the rep start to finish and full range of motion.
Much love and feel free to drop me any questions on anything training related. Stay strong 🙏