That's literally what 'homophobic' means lmao
Homophobia encompasses a range of negative attitudes and feelings toward homosexuality or people who identify or are perceived as being lesbian, gay or bisexual. It has been defined as contempt, prejudice, aversion, hatred or antipathy, may be based on irrational fear and may sometimes be attributed to religious beliefs.
just because they don't support LGBT+ doesn't mean their a homophobe. just means they don't like it, if they for instance say they don't support in a "they shouldn't exist" way then yeah that's homophobia but this person you just labeled as homophobic isn't a homophobe. LGBT+ just isn't their cup of tea.
coming from a trans masc gay man btw.