weird strings produced

Hi,
I'm using my heltec esp32 as simple temperature monitoring device:

1. via setInterval I sample my one wire sensors and generate strings (influx line format) that I push into array. Sampling is done every 300ms
   
2. again via setInterval I push the collected strings to influx via http post. This happens every 5 secs.
   
   

What's weird is that every 10-15 minutes I get error from influx because I'm sending corrupt strings. The errors are small — here & there one character is wrong.

Also, the device works for few hours and then stops sending data. Haven't been able to catch this moment and see tho logs yet.

How stable/dependable is espruino? Can I rely on it to control heaters and pumps (planned next step)?