Locked VFO B Shifts From 7074 to 7073 On Transmit When Using Split On Yaesu FT-991A? #Cat_RigControl

Cliff Fox (KU4GW)

I'm having an issue and I don't know why it's happening when operating on FT8 when I use the Split setting under the Settings, Radio tab. I was operating on 40 meters and set VFO A to 7074 kHz in DATA-U mode with AGC off and then pressed VFO A=VFO B  to copy the same settings to VFO B and if I'm transmitting as low as 400-800 Hz audio frequency when the FT-991A transmits it's shifting VFO B to 7073 for some reason. If I were transmitting at 1000 or above I would expect a shift up. I turned split off and chose "Fake It" in the WSJT-X settings because of it doing this. It had not been doing this until this past week it started happening, I'm thinking possibly due to operator error. Can anyone tell me what could be causing the shift on VFO B from 7074 to 7073 when I transmit and what would keep it from doing that when using the split VFO setting? Thanks in advance from a real greenhorn on a new to me mode.

Very 73 de 
Cliff, KU4GW

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