Who replaced the panel?
What circuits are reading 240v?

Can you please use a few more words to describe your problem? The way it is written it is impossible to figure out.

Who did the actual work and installed the braekers and the wire? Most homes with 240 vac coming in might welll expect some 240 vac circuits like for HVAC.

I see some electricians not make enough notes when changing panels, such as Low voltage ac wiring which is usuall a no brainer as many run with the supply wiring.
The phase circuits are on in multicircuits.
Sometime a white and black mabye on a 240 volt breaker, but when reconnecting, they may put the white on a neutral bar.
Or viceversa.
If the hot and neutral that supply a pane are reversed, you will get 240 volts on every other circuit.
How many circuits is this affecting?