Stop forcing gears, learn to shift smoothly during heel-toe. Sounds like your jamming it into place, probably have been for awhile but the new mounts are giving you more feedback. Id try shifting using just the base of your palm, very light pressure just allowing the shifter to go through the gates. And stop being so hard on the up shift, 1-4 are triple-synchro, 5-6 are single. It's not a dog box you can't just ram it into gear.
(safely)👍🏽👍🏽