There is some discussion about the matter in Berakhot 15b, relating to the precise reading of the Shema and it's subsequent sections. The wordsphrase בְּכׇל־לְבָבְךָ֥ areis cited as an example of where one is prone to slurring the words, and where one therefore ought to pause between enunciating the words.
Evidently, many reading traditions abide byJewish communities took this rule whento mean that they should pause between words that could be slurred in reading from Tanach. Morag writes that Yemenite Jews, for example, are careful to not to merge letters of adjacent words, whether the first has conjunctive or disjunctive accents (though he makes no mention of maqef) (העברית שבפי יהודי תימן, 65–6).
Katz notes that the Jews of Djerba also were careful to distinguish between words, even if there is a maqef between them. In fact, some readers would add an extra vowel between the words as a sort of separator, e.g. בן-נון as bine-nun (מסורת הקריאה של קהילת ג'רבה במקרא ובמשנה, 51).
There is some evidence that this was also the case in earlier stages of Hebrew. The בגדכפ"ת consonants were fricatives when they were proceeded by a vowel, unless they were lengthened;the consonant was geminated; in this case, the original plosive was preserved. Consequently, if words like עַד־דָּֽן were pronounced without a pause between them, we would expect the pronunciation to be either something like ʿaddān (if the dalet were geminated), or something like ʿaðān (if the dalet were not geminated). However, the niqud indicates the first dalet is a fricative, and the second is a plosive. This suggests that a pause was likely present when the fricativization process took hold (as early as the sScondSecond Temple period?).