GetEventsForHeightRange returning INTERNAL error

I noticed today, after yesterdays spork, that once I ask for events for a range including a block height less than 13950742, the status code coming back from the call is 13, meaning INTERNAL error. Calling GetBlockByHeight for such block heights will return a status of 5, meaning NOT_FOUND.

I’m trying to walk the chain and pick up deposit and withdrawal events on FlowToken.

Any advice would be welcome,
Jonathan