How to say “Politely acknowledge missed communication” professionally

Level 1: I haven't received an update regarding [topic] following our last discussion. Could you please provide clarification on the current status or any decisions made that I might have missed?

Level 2: I note the last communication regarding [topic] appears to have concluded on [date]. To ensure alignment and prevent any potential workflow discrepancies, could you confirm if there were any subsequent developments I might have overlooked?

Level 3: Per our established communication protocols, I am operating under the assumption that no new information has been disseminated regarding [project/task] since [date]. Please advise if this understanding deviates from the current reality, as I am proceeding based on the last available data point in our shared channel.

Level 4: Given the lack of communication on [critical item] by the agreed-upon deadline, I've had to make an interim decision on [consequence] to maintain progress. Moving forward, timely updates are essential to prevent further impact on [project/timeline].

Level 5: Heard nothing. Assume the worst.

Level 1: Following our last discussion regarding [topic], I haven't received confirmation on [specific action]. Could you please provide an update at your earliest convenience?

Level 2: We're keen to move forward with [next step] and are awaiting your feedback on [specific item]. We understand schedules can be demanding, so please advise if there's a revised timeline for this input.

Level 3: Our project timeline for [Project Name] is predicated on receiving the outstanding approvals for [Deliverable A] by [Original Deadline]. As we have not yet received formal confirmation, we are currently maintaining a 'pending' status, which naturally impacts subsequent phases. Please advise if a re-baselining of the project schedule is now required.

Level 4: Without your prompt input on [critical decision/asset], we are unable to proceed with [consequence]. This will inevitably lead to [delay/cost increase]. We require your response by [firm deadline] to avoid these impacts.

Level 5: Your silence speaks volumes.

Level 1: I wanted to check in on the status of [item] as I haven't seen an update since [date]. Is there anything I can assist with to move it forward?

Level 2: I'm reviewing our progress on [shared task] and noticed that I haven't received the expected input from your side on [specific component]. Could you let me know if there's been any progress or if I should adjust my timeline accordingly?

Level 3: To maintain our project's critical path, I've been proceeding with the assumption that the necessary data from [your task] would be available by [deadline]. As I haven't received a notification to that effect, I'm simply confirming that my current workflow is still aligned with the latest, albeit unstated, developments.

Level 4: The lack of your input on [task X] has directly impacted my ability to complete [task Y]. I need a clear ETA or the required information by [new deadline] to avoid further delays.

Level 5: Still waiting. Or not.