X-axis inconsistencies in line graph

[CreepyCatLady]

I have two line graphs that are showing reduction of item over time. The charts are identical besides the measure field, but the x-axis shows consistent first-of-month labels for one (this is the desired outcome), and random dates for the other. I have checked all settings and everything is identical. The data is updated weekly and at the same time for both fields. There is nothing that should cause these x-axes to differ. Is there a way to fix this?

What is happening with this one?This is the desired x-axis

[CreepyCatLady]

This is the first time I've ever posted a question and gotten zero replies after a day or two. I'm not sure whether this means this question is so elementary that everyone is ignoring it, or if it is something that is impossible to fix. I am very new to Qlik, apologies if this is something that should be obvious, but can someone reply and let me know something, even if it's just a dumb question?