Teletext was switched off in 2012. Ceefax and the BBC red button text were switched off at the beginning of 2022.
Do you mean subtitles on the BBC iPlayer?
If so then once the episode is playing, you need to press 'Up' on the circular four way pad to get the speech bubble to appear on screen, then up again to go to the bit of the menu where you can select it. Then when you're on it press OK to access the Subtitles option and then OK again to turn them on.
BBC Teletext is still Live is was never ever turned off after protests, so don't know where some of the info is coming from although you cannot get it on Virgin, only Freeview, my wife still uses it.
Using a old Humax PVR, from BBC 1 HD Freeview channel 101 the remote red button does give a text service.
The Freeview text services were scheduled to be phased out over 1 year ago at end of Jan 2022.
Given the widely published withdrawal plan it is not unreasonable that a new Freeview TV would omit a function that was not expected to be available when the product reached the customer.