Could you please try to increase the HIGH TRAFFIC LOAD in DCS up to 80%, then 90% then 95% to check the impact ?
The Traffic_load of the cell (DCS) is compared to the HIGH TRAFFIC LOAD threshold. If it is above, then the incoming “Preferred Band HO” is stopped. 70% is rather low.
By choosing a higher value, you will force the Pref Band Ho even if the DCS cell is already “quite” loaded.
Ensure that the A TRAFFIC LOAD and N TRAFFIC LOAD are set at standard values (not too small values, otherwise, the averaging is done too quickly… having a high threshold and quick average doesn’t sound too hot to my ears, initially… You could give it a try later though, as fine tuning optimization)