Before
A type: string prop constrained only by minLength was treated as a plain string: the prop was stored in a regular string field and the minLength constraint was silently dropped — nothing enforced it. Drupal core has no field or storage setting for a minimum string length, so the constraint could neither be enforced on input nor conveyed to translation systems (a translation shorter than minLength would have been accepted, then rejected by the component's own schema validation).
After
{type: string, minLength: N} is an unstorable prop shape, and every prop of an SDC — required or optional — must have a storable shape for the SDC to be eligible. An SDC with any string prop constrained only by minLength is therefore ineligible for Canvas: it no longer appears in the component library, and this takes effect on rediscovery (e.g. cache rebuild) — not only for newly added SDCs.
Code components are not affected: their prop schema never allowed minLength.
This follows the same principle as Required type: array SDC props now MUST specify minItems: 1: Canvas only supports prop shape constraints that Drupal's Entity/Field API can represent and enforce.
What to do
If one of your SDCs disappears from the component library after updating, check its *.component.yml for a string prop with minLength. Removing the minLength constraint restores eligibility — and matches what Canvas actually enforced all along. If a minimum length genuinely matters, enforce it in the component itself (e.g. render a fallback for too-short values), since no Drupal field type can guarantee it at input time.
