I was on a 24" LG IPS monitor for a few years without any real issues (24MK430BH or something I think). Also have a Dell P series 24" 1080p IPS and neither have a glare issue and both have quite a matte finish.
I purchased a 27" Dell QHD IPS however because I wanted something bigger/sharper and 27" 1440p is a great size for office work/multimedia but experienced eye strain and returned. I then ordered a 27" cheap budget Lenovo VA QHD panel (L27Q-35) which has beautiful contrast but still get a bit of eye-strain. Obviously I've adjusted for distance, warmer lighting, brightness, contrast, etc. One thing I noticed though is both the 27" new monitors I got have a coating which is definitely glossier than my 2018 24" LG or my 2021 24" Dell P-Series despite the new ones being categorized as matte. I then went on RTings to check because they show a reflection test and I see the exact same on most 27" monitors as what I tested at home. This to me implies that the 27" ones, at least the newer ones, have a slightly glossier coating which can obviously cause more reflection and hence more strain. Look at the pictures which are uploaded for reviews on RTings. The 27" ones on the reflection test show more of a clearer dot/circle whereas the 24" ones often show more of a diffusion of light and I notice the same with my 24" vs the 27" monitors I tried. You can check the same with a flashlight/phone camera flashlight. The other annoying thing is that most stores in my region don't carry 27" QHD monitors in store, they seem to be full of 27" FHD ones though so I can't check in store if they all seem to have this because when the monitor is off, I can clearly see which one has the glossier matte coating and which ones have the less glossy matte coating.
Asus ProArt PA278CV 27" 1440p IPS (notice the reflection shows more of a focal point implying the glossier coating even though it says matte)
Dell 2721D 27" 1440p IPS (again another 27" with the same more reflective focal point albeit less than the Asus above):
Dell S2421H 24" 1080p IPS (notice the duller focal point. I notice the exact same on my 24" monitors where it looks the same with the flashlight test and I don't get the same eye strain on these monitors).
I've checked several other pictures on RTings with the reflection test above and most of them show the more reflective focal point like the first two shots above including these other popular models:
27" monitors WITH more reflective screen coating where RTings image looks like first two pictures above:
LG 27GN880-B, Gigabyte M27Q, Dell S2721DGF and basically all other Dell S-series 27", Dell S2721QS, HP X27Q, ASUS TUF VG27AQ, Asus VG279QM, Gigabyte G27Q, Pixio PX7 Prime, BenQ EX2780Q, LG 27GL850-B, Samsung Odyssey G5, Dell UltraSharp U2720Q, and LG 27GL83A-B
Unfortunately, I couldn't find many pictures on RTings of 27" monitors WITHOUT the more reflective coating which looks like the third picture from the 24" monitor above but here are a few I did find. Only one of them is QHD and actually somewhat available:
LG 27GN800-B (2021 model), HP 27F (this is 1080p not 1440p), HP 27Q (no longer available anywhere), Samsung Odyssey G4/G40B S27BG40 (this is 1080p not 1440p), Dell G2722HS (1080p not 1440p), MSI Optix G272.
I do wonder if it's possible to put together a database of this for 27" ones but for 24" ones from what I see including on RTings, they mostly look like the third picture above with the less reflective coating similar to the two which I have.