aiogram.utils.exceptions.ValidationError: Media group must include 2-10 items as written in docs, but also it works with 1 element

def medlink(n):
with open('pnglinks.txt') as file:
    res =  file.readlines()[n-1:n]
    print(res[0])
    return res[0]

@dp.callback_query_handler(Text(startswith='n-'))
async def send_theory(call:types.CallbackQuery):
actnum = call.data.split('-')[1]
if actnum == '1':
    media = [InputMediaPhoto(photo) for photo in medlink(1)]
    await call.message.answer_media_group(media)
    await call.message.delete()
    await call.message.answer(text='1_Кинематика',reply_markup=InlineKeyboardMarkup(row_width=1).add(InlineKeyboardButton(text='↪Назад',callback_data='tospravka')).add(InlineKeyboardButton(text='⬅Гл.Меню',callback_data='main_menu')))

await call.answer()

Почему этот код вызывает такую ошибку?

aiogram.utils.exceptions.ValidationError: Media group must include 2-10 items as written in docs, but also it works with 1 element.

Если возвращаемый аргумент такой:

fiz1 = ['https://cdn.discordapp.com/attachments/770344822955049022/1090335575074156595/1_kinematika-1.png','https://cdn.discordapp.com/attachments/770344822955049022/1090335575321624626/1_kinematika-2.png','https://cdn.discordapp.com/attachments/770344822955049022/1090335575560704070/1_kinematika-3.png']