I would humbly suggest that maybe your cables have 'stretched' - after 1100 miles they might need a little adjusting.
The derailleur has a spring which tries to push the cage & therefore the chain down to the small chainring (cog). The cage is moved the other way by the gear cable which is pulled back against this spring and held at certain points by the 'click' of the shifting mechanism in the STI brake/shifter. If things have slackened/slipped a bit, the click will be holding the cable at a point where the derailleur is not properly lined up with the chainring.
The eos seems to come with Tiagra kit, which is jolly good. If you look where the cable coming out of the left-hand shifter meets the 'downtube' you should find a handy barrel adjuster. This can increase or release the tension on the cable, bringing the derailleur back in line with the chainrings.
Shift the rear gear into a middle cog at the back, then shift down to the granny ring to release the tension on the gear cable. Now rotate the barrel adjust a quarter turn anti-clockwise ("undoing it" as though opening a tap) and try shifting your front gear up to the middle ring, then up to the big ring. Basically, try repeating this a few times either way, quarter turns up and/or down, until it's shifting nicely.
The way I remember it is that it is counter-intuitive; "undoing" the cable adjuster tightens the cable - ie pulls it away from the way the spring wants to go.
Only hesitation is that it happens when pushing on the right foot - it may be that this coincides with the 'ramps' that make the chain move smoothly from one ring to the next, and it's catching cos of the misalignment.
hth