Do you ever watch a whole bunch of ads only to return a short time later to see that your ad boost timer has either reset completely or the time has diminished far too quickly?
After gathering some info and looking into this, it seems that this is a visual error for a portion of our players. Please try switching between planets to see if this helps restore your timer properly.
In other cases, however, this is caused by the timer running a touch too quickly and there aren't workarounds for the time being. We are working on a permanent fix for this and the solution should be available soon (as of July 20 2018)
Thanks for your patience!