It appears your ancestor served under both Capt Deibler and Capt Weaver.You might be able to find the references in the PA archives, that are listed on this DAR record from www.DAR.org
He is listed as a VOL - volunteer - which means he may have volunteered for a specific battle/time period/regional call, some vols served 3 months, some 3 yrs.Could have served, gone home, re-enlisted later.Not that uncommon.
Good Luck. HOFFMAN, JOHN NICHOLAS
Ancestor #: A056409
Birth:3-21-1749 BERKS CO PENNSYLVANIA
Death:4-28-1814LYKENS TWP DAUPHIN CO PENNSYLVANIA
Service Source: PA ARCH, 2ND SER VOL 13 P 390; 5TH SER VOL 7 P 347