Block explorer zcha.in -question on displayed data

Why does this address show a negative transparent balance?
Transparent Balance -0.01098145 ZEC

Total Sent1998.32324472 ZEC
Total Received1998.31226327 ZEC

Actually I’m seeing negative balances on a number of addresses.

Perhaps they started pruning their blockchain?
https://zcashnetwork.info/address/t1TcJBq14YQeAytE3fzykKWefhTTHtMDaez