In adult guardianship, what would happen if the ward refuses to acknowledge guardianship?

Legally, the guardian has the same authority as if the ward were a minor child.

How they actually exercise their authority varies widely.

The guardian *could*, as an extreme measure, call in the police to physically restrain the ward. The ward could be a "grown adult", but if he/she is under legal guardianship, it's because a judge has determined that the ward is not a responsible person capable of making his/her own decisions.

If / when the ward commits a crime, or damages property, or is the victim of a crime, the guardian could be charged with failure to supervise.

The ward isn't refusing guardianship. The ward would like to have social interactions with others as is their right and the guardian's responsibility.

If the guardian doesn't trust the ward's judgment, perhaps the guardian should accompany their ward.

You've given basically no information/context/details so...