My boy went through something really similar around that age, and what helped us was adjusting the timing, because sometimes the meltdown is actually a sign they're already overtired by the time we start the wind-down. It is worth trying to start the whole bedtime routine a bit earlier, maybe 30 to 45 minutes before you usually do, so you catch them before they hit that second wind or total exhaustion stage. Some kids at this age also go through a sleep regression tied to development, so it may be a phase that passes, but if it drags on you can always check in with your PD to rule out anything like teething discomfort making it worse.