No. Amazon wouldn’t collect the VAT on domestic sales - it’d be your job to report your VAT figures to HMRC each quarter. They would though stop charging VAT on the fees and you would account for them as “reverse charge” - essentially accounting for them as both an income and an expense so they are neutral.
Did you check the fees before you listed? Are the measurements right on the listing? Are they all UK - UK sales? Are these all the same items?
The actual fees including VAT for your item is the £4.42. The £2.96 is because the referral fee isn’t being charged, I don’t know exactly why, but other sellers have mentioned a promotion for new sellers that has something like no referral fees for certain days at the start of a month.
UK. If your business turnover is less than £85K VAT is not compulsory. You can register for VAT voluntarily.