Where I used to work, a union was foisted on us. The contract language specifially forbade uion members going on strike.
WTF!!??
That is common. Part of being in a union is that you can only strike when the union calls one. That’s part of why companies sign contracts with unions. Going out on strike without union authorization is called a ‘wildcat’ strike, and the idiots who do it can end up with BOTH union thugs and corporate goons after them.