Town have now lost three of their past four home games in the Combined Counties Premier Division South, but have picked up ten points out of a possible 12 on the road.
Johnson has urged his side to improve their home form.
“When we’re playing at home it looks like we feel the pressure a bit,” he said.
“We had no mobility in the side against Guildford – it was not good enough.
“It’s difficult to put my finger on it. Our warm-up was ideal on Saturday and was one of the best since I’ve been here. When I arrived we had no pace or mobility in the side. We’ve brought players in but still don’t have enough mobility.”
Guildford took the lead with just four minutes on the clock. Jamil Saleh appeared to be yards offside as he ran through before playing the ball through to team-mate Cameron Gyeabour.
It took the hosts the best part of 20 minutes to fashion a real chance of their own, when Kainen Oragbade created space for himself in the opposition area before forcing a sharp save from Guildford keeper Stuart Norman.
Then, on 28 minutes, Town’s luck turned against them when keeper Connor Beattie – playing his first game for Farnham this season – suffered a nasty cut, requiring stitches, when saving bravely from the lively Gyeabour.
Three minutes later, Guildford doubled their lead when the home side’s defence simply went to sleep as Guildford worked a free-kick routine from the training ground to find Scott Costello with all the time in the world to slot home past James Ferguson.
With both sides spurning second-half chances, it was Farnham who finally found the net on 64 minutes, when a neat ball from substitute Jamie Hoppitt played in Connor Young, who coolly finished for his ninth goal of the season.
Stirring memories of the comeback against Abbey Rangers, the goal gave hope to Farnham’s supporters, but there would be no repeat.
Guildford extended their lead on 72 minutes when Salah turned provider for a second time, playing in Leon Dadley to put the match beyond the home side.
As the spectators began to file away, there was just time for Guildford to miss a last-minute penalty when Zeid Hannachi shot at a comfortable height for Ferguson to make a simple save.
Johnson praised Young for his goal, but felt he could have been more clinical.
“Connor is a talent, but he missed a couple of other chances – including a header from a couple of yards out.”
Farnham bounced back from the Guildford defeat with an impressive 2-0 win at Horley Town on Tuesday night. New arrival Matt Surmon scored the second goal.