I'm not an expert about the FCC repack of TV channels, but from looking at the data on rabbitears.info, it looks like WVIZ is moving from real channel 26 to real channel 35. They are in phase 4 of the repack scheduled to be completed by August 2nd. Could be that they are doing some work to the transmitter or antenna that is affecting their coverage. They should be in the testing phase of their new channel assignment. Plan to re-scan your TV on August 2nd so you can pick up the new channel.
https://www.ideastream.org/plan-to-scan
In my area several channels have some reception problems as they are operating on temporary antennas or transmitters as part of the repack process.