Thoughts on cheapie hpt

Wondering anyone’s thoughts on false positive/indent with these cheapie tests? I took this with FMU and got what I thought was a vvvfl. Freaked out and grabbed a FRER and tested with same FMU. FRER was a stark negative. Like absolutely nothing. So I’m confused because I thought they should be more sensitive than the cheapies, which is making me wonder if the cheapie was faulty in some way. Obviously I will continue to test the rest of the week with FMU, just wondering anyone’s thoughts. We had a miscarriage a year ago this month and haven’t been able to get pregnant since, so I’m trying not to get my hopes up.

First picture was taken within time frame, unedited. Next picture is inverted, then grayscale. Last picture is unedited, taken after the test had dried. I am about 10 DPO, AF due in 4 days. TIA!