If I understand you correctly, the image in Lightroom is a TIF file which you try to edit in Photoshop.
I have check this on my machine and if I use the "Edit a Copy" option I already get a TIF even though I also set PSD in the setings for editing in Photoshop.
If I use the "Edit a Copy with Lightroom Adjustments" I get a PSD as result.
I think this is a normal behavior because if you use "Edit a Copy" a copy of the original image file will be create first and then it's open in Photoshop. Editings wre saved to this file. There's no format change to PSD.
Try to send the appropriate image to PS by using the "Edit a Copy with Lightroom Adjustments" setting and see what happens.
My System: Intel i7-8700K - 64GB RAM - NVidia Geforce RTX 3060 - Windows 11 Pro 26H2 -- LR-Classic 15 - Photoshop 27 - Nik Collection 9 - PureRAW 6 - Topaz Photo AI