I have seen many inactive ones despite receiving enocouragement, invites to gatherings, invites to home meals, visits and so-on but still remain spiritually lazy.
Here's what is really happening. Those judged by you as spiritually lazy are just trying to be kind in accepting those invitations. Jehovah gave humans the ability to reason, on their own, and therefore do not need men dictating every thought, every movement, every sentence to them. To say the JW's reason from the scriptures is completely false. The GB rationalize from the scriptures, then write it down, then tell all of the R&F what to believe, how to act, what to think, what to wear, and who to accociate with. The GB rationalize from the scriptures in order to prop up their absurd rules. Those who are in the org, are not thinking for themselves, that would be a sinful act would it not? To think for oneself and perhaps disagree with anything the org says might cause a real problem.
So, the ones trying to get away, fade, escape, will be polite about it. They will accept invites, or not, they know what you are doing, but they do not want to be rude, or cause problems especially if they have family still in. You are misreading the events, they are not 'spiritually weak', (an observation that is in no way your business, or within your scope of authority to decide) they are trying to withdraw from a toxic organization.