Identify the specifics of the drop:

Is the drop a sudden occurrence or a gradual trend? Understanding the timeline can provide initial insights. A sudden drop could suggest technical issues, while a gradual decline might indicate product-market fit problems or increasing competition.

Internal Factors:

• Product Changes: Check if any recent updates or feature launches have occurred that could have caused this drop. This can be done by looking at the product update logs and cross-verification with the timeline of the drop.
• Technical Issues: Consult with the tech team to see if there have been any recent technical issues such as bugs, server downtime, or performance problems that could affect user experience specifically in Ahmedabad.
• Customer Support Data: Review the recent customer support interactions from Ahmedabad users. Increases in complaint volume or severity could indicate specific issues leading to user drop.

External Factors:

• Competition: Has a competitor recently launched a major initiative, marketing campaign, or a promotional offer that's stealing our users?
• Regulatory Changes: Are there any new regulatory or policy changes that could have impacted our operations in Ahmedabad?
• Market Trends: Look for any shifts in education trends, user behaviour, preferences, or other environmental factors in the Ahmedabad region.

Understand the user segments affected:

Analyze the data to understand which specific user segments are showing this drop. Break down by user characteristics such as student age, grade, courses enrolled, device used, etc.

Review related metrics:

Examine other related metrics such as course completion rate, session length, number of courses enrolled, etc., to understand if the drop is due to lower engagement or dissatisfaction with the content.

Create a hypothesis and validate:

Based on the collected data and insights, formulate a hypothesis for the decline. For example, it could be that a new version of the app has technical issues on certain devices popular in Ahmedabad. This hypothesis then needs to be tested and validated with data or user research.

Plan remedial actions:

Once the root cause is identified, work with the relevant teams to plan and implement remedial measures. It could be fixing a bug, launching a marketing campaign, adding more local language content, etc.

Monitor the metrics:

After implementing the changes, continue to monitor the DAUs and other related metrics to see if the situation is improving.

In summary, as a PM, it's crucial to understand the root cause of a problem before jumping into solutions. The steps above detail a systematic approach to diagnosing the problem and arriving at an effective solution.