Strange energy values every day

Hi! I’ve got a solar log base 100 and my energy values are looking quite strange. Very day at 0:00am my yield total is adding the amount of kwh from the last day. Then one hour later it removes a part of these kwh’s (1:00am) and after 5-5.5 hours (6:00-6:30am) it removes the rest.

Maybe as a table it would be more meaningful:
11:59pm → yield_total = 1234 kwh | yield_day = 100 kwh
00:00am → yield_total = 1234 kwh +100 kwh = 1334 kwh
01:00am → yield_total = 1334 kwh -20 kwh = 1314 kwh
06:12am → yield_total = 1314 kwh -80 kwh = 1234 kwh

Here are the sensor statistics (yield_total):

Thank you very much for your help!