Sounds like the steering rack is jamming or otherwise failing. Suggest not driving it until sorted. A chassis failure could cause this by placing a distorting force on the rack. A close inspection with front end on axle stands may reveal the cause.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone