Trying to get a better result on Chrismast and new years holidays

Hi, we are having a difficult to adjust the model on holidays dates. We passed the holiday df into the model, with the upper and lower columns, and also the scale parameters, for all holidays dates. Although, we are facing a not good enought result on the holidays, specially for the chrismast and new years dates.
The serie has a really discripance between week and weekend days, and that seems bo be a problem to. Predictions for weekend are really week.
We have trying adding new regressors such as "is_weeked" or change the parameters scales;

edit: We have daily date, and 10 year of data
Any sugestions? Thanks in advance!