The report for that day in National Archives HW 13/20: "Summaries of GAF operational activities (2 Mar–22 Aug 1944)" says:
21/22 Biscay
A. Recce
(I) Early operation by 3.(F)/123 as a preliminary to shipping offensive by III./KG 100. A/c up 0535–0850, sighted naval units in 14 West 6941 at 0730.
(II) Routine night security recce by 3.(F)/123 with 1 a/c heard 0041–0046/22.
B. Offensive
As a result of the above sighting report at 0730, III./KG 100 was ordered to carry out an attack with all available forces. Accordingly Flak batteries in La Rochelle area were warned of fly-out of 7 Do 217 from 1145 onwards.
Results: 5 a/c identified in W/T, 1151–1437.
Escort Group 14 reported being bombed in 48 degrees 16 minutes N, 05 degrees 30 minuted W. British claims are 5 a/c destroyed, 1 a/c probably destroyed, no German claims available.
NOTE: Further reports of naval units sighted west of Brest 1345–1351 were promulgated by Fliegerkorps X at 0045/22. This suggests an intention to repeat the attack to-day 22/7.
Bundesarchiv RL 2-IV/40: "Invasions-Kalender Normandie 1. Juli 1944 bis 1. Aug. 1944 (Durchbruch bei Avranches)" says eight Do 217 operated, seven Hs 293 were dropped and they damaged a destroyer as well as shooting down a Westland Whirlwind.