@MdFI'm having exactly the same issue as you've described since last week though it hasn't resolved itself as yet in my case.
With time of use enabled I Iobserve that once batteries are fully charged up by mid day on full sunny day it drops PV production and immediately starts discharging batteries and grid supplements the load. Time of use must be disabled during the day in order for PV production.
towards the evening around sunset, I need to enable time of use in order for batteries to supply my load. If not done, grid is constantly supplying all load with minmum battery discharge. In some instances it uses grid to charge batteries.
All this nonsense started about 2 weeks ago after Deye support upgraded my inverter software. Prior to this I had absolutely no issues.
I'm pulling out my of hair with this issue and can't seem to fathom out what to do. I've logged a call with deye and awaiting confirmation if the inverter software can be downgraded.
As a matter of interest, what is your inverter software version?