What sins are forgiven between Juma?

It is narrated from the words of (Abu Hurayra, may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allaah be upon him) said :
“(Performing) five (daily) prayers, (participating in each next) Friday prayer (after the previous one ) and (observance of the fast in each next) Ramadan (after the previous one) atone for (sins committed) between them, unless there were serious sins among these sins. See Muslim 233

Ibn al-Qayyim, may Allah have mercy on him, in his book “Javabul-Kafi” Noted that the Quran and Sunnah showed the unanimous opinion of the companions of the Prophet (peace and blessings of Allah be upon him) and their followers, as well as the entire community, that sins are divided into major and minor. Javabul Kafi
Imam Al-Nawawi (may Allah have mercy on him) said : “This means that all sins will be forgiven, except for serious ones. This, however, does not mean that absolutely all sins are forgiven, except for serious ones – some minor sins can also remain unforgiven. This understanding is possible, but the context of the Hadith refutes it. Qada ‘Iyad said: “The forgiveness of sins mentioned in the hadith, unless it is about grave sins, is the madhhab of Ahlu-s-Sunna. Heavy sins are forgiven through the repentance or mercy of Allah Almighty. And Allah knows better about everything.  Sharh “Sahih” Muslim