Interestingly, this page seems to contain data only until year 2014, but the graph next to Estonia in the grandparent link does show an increase on the right side. Maybe Estonia did indeed experience some changes in overall distribution loss in recent years?
Elering reports only their part, the very high voltage transmission losses. Then there are the distribution losses on the local level are they're about 4%.
'kaod' is losses, this table shows losses from bruto production.
Either someone has been sending wrong data to the world bank or there is some issue with interpreting them before importing to world bank.