It is overcontrolling laterally. Common among lesser experienced pilots, no disrespect intended. Fair enough to come up with technical explanation but I have witnessed this frequently as a 737 instructor on the aircraft and simulator. Often I would tell the trainee to relax and reduce control input and lo and behold due inertia and good ol’ Newton the aircraft continues in a straight line. There is no need to fly the aircraft like Lady Penelope’s driver, Parker in Thunderbirds. You may need to be slightly, ahem, older to get that reference. I would humbly suggest more frequent manual flying when appropriate on the line rather than depending on automation too much.