Meter readings

Around 18 months ago we had our electricity meter changed to a smart meter. The TADO problems that followed were :

1, it wasn’t possible to enter the meter readings for the new meter so I had to calculate how many kWh we had used that day and add it to the original meter reading.

2. This manipulation worked well until the meter reading exceeded 99999 and the TADO site would not accept any reading over that number not would it accept the actual meter reading of the new smart meter.

any suggestions on how to enter meter readings for newly installed meters?

thanks