After further investigation, I found that the problem was related to how the number of ranges in the LiDAR scan was being calculated. The formula used for calculating the number of ranges is:

"num_ranges = int((scan.angle_max - scan.angle_min) / scan.angle_increment)"

This formula calculates the number of ranges based on the angle range and angle increment, but because it uses integer division, it rounds down the result. The issue arises because the scan.angle_max and scan.angle_min values in the configuration file were set with limited precision (3.14), leading to a mismatch in the expected number of values.

So, the solution was to adjust the precision of the angle values in the configuration file. By increasing the number of decimal places for the angle_max and angle_min values (e.g., changing 3.14 to 3.1416), the calculation of num_ranges became more accurate and the number of ranges matched the expected value.

This small change allowed the merged scan to be processed correctly and the map was generated without issues.