6 month old won't go down until 11pm

[Ohdearducks]

The past couple of weeks my 6 month old has started to stay awake until 11pm and I can't seem to get her down any earlier anymore.
She has a bath at 7.30 then story and feed and in to bed by about 8.15 each night, she used to sleep until 1 or 2am then have a feed and wake up 2 hourly after that. The last two weeks however, she goes down after her bed time routine and will only sleep 20 minutes and then wakes up as if it's morning time and will stay awake until 11pm! I'm spending 3 hours every night trying to get her back to sleep, I'm going mad with exhaustion as she still wakes at 1,3,5 and 7am help me someone please.
P.s my DP does occasionally stay up with her and give expressed milk but I usually get up and feed her because it's easier than listening to her cry waiting for milk to be warmed.

Is she having a nap late in the day so not as sleepy by bedtime? Or could be a growth spurt if she's cluster feeding? Or teething? hopefully it's just a phase and she'll stop this pattern as quickly as she started it. I know it's hard though so I sympathise.

She naps around 4pm for around 20-30 mins, I can try and keep her awake today to see if it makes a difference.
Not cluster feeding at the moment, yes to teething, she also started solids around the time this started happening could there be a connection?

Starring weaning definitely messed with my daughter's sleep and it has been the same with friends' babies. That might be your culprit!

Oh no really? So I guess I've just got wait this out? I'm absolutely fraught with exhaustion

8.15 sounds like a late bedtime. Could she be overtired? When does she nap?

Cross posted. Similar nap time to us. But if she woke up at 4.30 here, it would be bath at 6, stories 6 30, asleep at 7. If she goes later she'd be a nightmare at night.

8pm was just the natural time she fell asleep for bedtime so we just did the routine for that time, maybe trying to keep her awake at 4pm and doing bed time earlier will help? She usually wakes for the day at 7am naps at 10 am then 1pm then 4pm.

I tend to find that age they sleep again 3 hours after waking, her naps are bang on for that so I'd keep naps the same but try putting her in cot earlier just as an experiment.

I'll try bath for 6.30 and in to bed for 7pm tonight and see if it helps. Thanks for your advice

Meant 6pm not 6.30

This was both of my children. Starting school moved bedtime to 9pm. We just embraced it (but it suited us because we're night owls too).