Are Bupron XL vs SR the same?

I got prescribed Bupron 300 SR recently but I can't find the SR formula anywhere online. Wherever I see it's just XL (Xtended/Prolonged Release). Are they the same or different because I was taking Bupron 150 Prolonged Release for a month and it was ok. But since I started taking Burpon 300 XL because I couldn't find SR, my sleep has been fucked up recently. Anyone got any clue?