I am not sure about his perspective of not texting you. But being a Muslim myself there are certain rules of fasting. Fasting is not about just to not eat and drink. There are numerous things behind it. First is you gotta pray 5 times without it your fast is null and void. Reading Quran is mandatory as well. Plus one has to refrain from any activities which might be considered as a bad deed. Like stalking a women. Speaking lies or bitching. Maybe I think cause of all these reasons he avoids talking to you and text late in the night only. This is my presumption. I can be absolutely wrong about it as well. While fasting sexting or being romantic is complete No No. Talk to him about it I'd say. My intention was just to clarify the terminology about fasting which can be one potential reason he isn't texting.