Is this a known phase - 21 month old howling whenever her goes in cot

[Liveinthepresent]

I am not necessarily seeking advice but maybe a bit of reassurance..
DS is 21 months now - I spent a lot of time on here during the 18 months it took for him to STTN.
The last couple of months have been a doddle - reliable lunchtime nap and 7-7 at night - very rare night wakes and easy to settle.
All good and I have finally started to catch up on sleep and feel like a proper person living a proper life again.
Anyway the last week or so he has just randomly started properly screaming whenever we put him in the cot for sleep. One night it took over an hour to settle him and the same at nap time the following day.
Last night we woke at 4 am and did the same - although miraculously he did settle quite quickly.
I have a vague recollection of my DD doing something similar but no idea how long it lasted and what age she was!
I don't have much of a clue whats causing it.
Anyone else been through similar? really hoping it might pass before we go on holiday next weekend!

What time does your ds usually nap?

I remember my ds having a bit of a 'blip' at around that age which did eventually pass, but around the same time we also ended up having to shift his nap a bit later so it started at 1pm instead of 12.30. Hth.x

thanks for the reply.
I guess the clock change may also not have helped yesterday.
Am not sure it is timing related as he is normally absolutely shattered when I put him down at 1 - he goes at 12.30 at nursery.
the good news is tonight was much better - he tensed up and started crying as we approached his cot but although he did howl for a couple of minutes he then crashed straight out.
Am hoping its developmental or something - and selfishly praying it won't sabotage our evenings/nights on holiday!

Had the exact same thing at 21 months. Just stuck with the same routine but slowed it all down a bit. It eventually passed and he's a great sleeper again. Wish I could give you better news, but it took about 3 weeks! And don't give up on the nap

I had the exact problem with my ds when he hit 20 -21 months. Previously fab sleeper 7-7 self soothing etc.
suddenly, without any warning or anything significant happening he decided he didn't like his cot and would literally scream blue murder every day nap and night nap.
I'm soft and so couldn't do the whole controlled crying plus ds would get so worked up he was sick.
I then decided after 6 weeks enough was enough and got a toddler bed and redecorated his room into a big boy room with rockets and moons and stars which he loves.
He gets into bed fine but either me.or dp have to stay with him until he falls asleep. We then sneak out.
sometimes he sleeps through, others he wakes and needs a bottle Togo back to sleep. sometimes he comes.in with us.
I. know what you're going through and it sucks. real shock to the system but bear with it and good luck!