HK have a lot of issues to deal with at this time.
Not least of which is comparatively little air-freight, with ‘normal post’ not being prioritized.
Also surface freight slots (on ships) are in short supply, with containers in the ‘wrong’ location, and anecdotally, prices rising from $2,500 to $10,000 - $12,500.
‘Normal’ freight is/was quoted at 18-30 days to the UK, up to 5 weeks to the US.
My item is tracked, but it took a week to show up on HK post tracking, a further month to clear HK post outbound, handed to the courier & is currently “Handed over to carrier / Left for destination”
According to HP post you have 3 months for the sender to start a claim (proof of postage required).
Provided you paid by credit card or PayPal (but not if you paid by friends & family), I would consider under 3 months from postage date the time to start inquiries with the sender, or under 6(?) months with PayPal.
I once had a problem with an overseas item, contacted the seller, who refunded without question. The item turned up two months later, so I contacted the seller again, who said keep it, so not all bad news.