Not really. I can't prove that at no point in the Middle Ages did anyone of any social class or age, anywhere, believe that the stars were just big candles really far away, but this was never a common understanding upheld anywhere, unless you allow for a really generous definition of "candle". (And of "really far away"). By the Middle Ages, this idea of what stars literally-or-metaphorically were (candles? spilled milk?) and what stars did was deader than disco. Many individuals in the Middle Ages were keen on astrology and in general on using the heavenly bodies to mark the passage of time or to predict future positions of the heavenly bodies. This continued more or less continuously from Classical traditions of the same, and was especially developed in the Middle East, where scholars retained freer access to Greek-language Classical texts. In Western Europe, the Venerable Bede was touting using the stars to calculate the date of Easter (and from the date of Easter, the whole rest of the liturgical year) by the 7th century; by the 10th century, Western European scholars were venturing to the Middle East (or to Arabic-speaking/Arabic-influenced areas like Spain and Sicily) to learn from Muslim sources and transmit the same information to a broader European audience in Latin. Obviously this is scholars and monastics traveling abroad to learn about the nature of the stars. Were there folk beliefs about the nature of the stars? Probably. But the orthodox academic or theological understanding of astronomy and the ordering of the cosmos was never just "the stars are candles, the Sun and Moon are also candles".

The idea of fixed stars in Ptolemaic models of the celestial spheres might be what the idea of stars-as-candles in the Middle Ages is misunderstanding -- stars not as variously sized 3D gaseous bodies arrayed at different distances from Earth but all located at a fixed distance from Earthly observers, stars as either literally or for-the-purposes-of-our-calculations being points of material emitting light stationarily embedded in a uniform sphere. These bodies (as well as the Sun and Moon) might be theorized as being made of fire, but the idea of "what stars are made of" was less interesting in a practical sense and more philosophically provocative in terms of what makes up an ordered universe or a five-elements-oriented understanding of the composition of major features of the universe. The idea of them being made of fire was not especially controversial, but that's not quite the same as literally conceptualizing them as literal wax/tallow candles with wicks and whatnot.