Is a self-locking relay the same thing as a latching relay?
According to Mozar Tips YouTube video the relay is not latching.

According to the Amazon link the unit is HiLetgo 5V 1 Channel Latching Relay Module with Touch Bistable Switch MCU Control. It's not the relay that is latching - it is the module.



Figure 1. The board sports an STC 15F104E MCU. That's what's doing the latching.

Any device using the SRD-05VDC-SL-C relay will open its NO contact when the power is removed.

A latching relay is shown below.



Figure 2. Go to HomoFaciens and click "Start animation" to see how the pawl mechanism is advanced on every impulse of the relay coil.