for the past few days i have been having an issue where the corners or edges of a model i am trying to print start curving up off the bed slightly. it loses contact with the bed and after a period of time more of the model starts to come off the bed. i have attached a couple of photos to show what is happening.

What can i do to fix this issue?

Any of the following or combination: Glue stick, reduce cooling, raise ambient temperature(enclosure), print at a lower temperature, print with brim, print slower.