Unexpected decline in chart and results on holiday

Has anyone else noticed an unexpected decline in results and on the charts for stock trading strategies today, when the market is closed for a holiday?

My new strategy, ETF Trend Trader, has a decline of over $200 in its cumulative results and chart which occurred sometime after 7am (ET) this morning on a market holiday. It wasn’t due to the monthly subscription cost, since the strategy is only about 2 weeks old and the first month cost was already deducted.

I then checked a few other strategies that trade stocks and saw they also had similar declines today, so it may be a systemwide problem. Perhaps it had something to do with this weekends maintenance?