In this case soft sign serves a dividing function and also soften consonant followed by it , it makes you to pronounce the word as it would be two but without delay

Divided ъ: before е, ё, ю, я: 1) after prefix enвы with consonant (подъезд, съёмка) 2) after prefixes from another languages like ад-, диз-, ин-, интер-, кон-, контр-, суб-, пер-, транс- (адъютант, конъюгация) 3) after smth "двух-, трёх-, четырёх-" (двухъярусный, трехэтажный) divided ь: before е, ё, ю, я: 1) in some words (крестьянин, вьюга) 2) after root before ending (соловьи, листья) 3) before "o" in some words from French (медальон, шиньон) We use both to devide sounds.

In this case 'ь' makes 'ю' to sound as [ju], not just [u]. For example, in these words - костюм, рюкзак - 'ю' sounds as [u].

It sounds like комп'ютор (комп-йу-тор). In this word "ь" just separates a consonant and a vowel and has no special effect on how "п" is pronounced.