Cloud-backup your phone, factory reset it, set it up again with a phone number, a different messenger app to the one you currently use and download your idk, 20 most recent pictures to your galery and set one as your background.
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You will still be able to make phone calls if needed
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You will still be able to send messages on for example Telegram even tho you usually use Signal
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The phone will not look like a burner as it has some personal content on it
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The phone will look personalized and thus less suspicous together with point 3
Edit: You don't even have to actually set them up or even open them at all, but maybe even download a shopping list, a notes app, two games, all in all it should take like 10 minutes to make your phone look less suspicous as opposed to the other advice to just factory reset it.