As far as I know, the Hanafis typically pray Fajr later outside of Ramadan due to the following hadith:
Rafi bin Khadij said:
قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: أَسْفِرُوا بِالْفَجْرِ، فَإِنَّهُ أَعْظَمُ لِلْأَجْرِ
"I heard Allah's Messenger saying: 'Perform Fajr at AI-Isfar, for indeed its reward is greater.'"
- Jami` at-Tirmidhi 154
Al-Isfar means when the dawn breaks and lights (i.e. before sunrise).
But in Ramadan they pray it earlier due to this hadith:
Narrated 'Abdullah bin 'Umar:
أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ بِلاَلاً يُنَادِي بِلَيْلٍ، فَكُلُوا وَاشْرَبُوا حَتَّى يُنَادِيَ ابْنُ أُمِّ مَكْتُومٍ ".
Allah's Messenger (ﷺ) said, "Bilal pronounces the Adhan at night, so keep on eating and drinking (Suhur) till Ibn Um Maktum pronounces the Adhan."
- Sahih al-Bukhari 620
The reason for the 2 adhans is explained in the answer provided by @Medi1Saif in the question Did Masjid e Nabawi had two Muezzins during the Prophet's lifetime simultaneously?:
The idea for the two adhans is that the first adhan for fajr is held before the time "Bilal pronounces the Adhan at night" so that people can wake up prepare themselves to go to the mosque etc. or as clearly described in the hadith to be prepared that a second call -on time- "till Ibn Um Maktum pronounces the Adhan" comes and that will be the call for the start of fast. This practice is still in use in many Muslim countries and considered as sunnah.
This suggests that they prayed after suhur ended, which is earlier than Al-Isfar.
So according to Hanafis, outside of Ramadan fajr is best prayed at Al-Isfar and during Ramadan after suhur ends, in accordance with these ahadith and the Sunnah.
Sources:  and