Strange sidebearing problem with a couple of characters on font. (ubuntu titling)

Question

I have a LGPL licensed font, that I am currently using for my website. The font works well, except for a couple of characters (. and ,).

At times, depending on which characters are surrounding it, the sidebearings act as if they are negative. That is, the comma or period actually appear on top of the previous character, as on this lowercase H below:

I tried loading it into FontForge, but the previews seem to work just fine and the spacing seems correct. This is not a problem, with a specific browser, because it happens in all of them. The font file is located on my google drive

The strangest part of all of this is that the problem only happens with alpha characters and everything works fine with numbers.

I tried to copy character 201A to the comma (002c), but the problem still persists.

As a side note:
If you know of a similar font, please suggest it.

Answer 1

If it only happens with specific character combinations—that would be kerning.

Search for any problem kerning pairs in FontForge and adjust the values accordingly.

You can read about metrics and kerning in FontForge here:

• FontForge Documentation – The Metrics Menu

Answer 2

I opened the font file you provided in FontLab and can confirm that kerning is definitely the problem. I'm not sure why, but someone has modified the values in the font you have. I'd suggest, instead of mucking with the kerning on the file you have, download a fresh version from Font Squirrel: https://www.fontsquirrel.com/fonts/Ubuntu-Titling

I just confirmed that the Font Squirrel version of Ubuntu Titling does not have the same issue, and as a bonus has some nice OpenType features that yours doesn't. Attached is a screenshot of FontLab's Metrics window showing proper kerning of these characters.

Hope this helps.